[PATCH 0/1] FAQ for common user questions

[PATCH 0/1] FAQ for common user questions

[brian m. carlson]

Git is an enormously flexible and power piece of software, but many
people find it confusing and hard to use.  Over the time I've been
contributing, I've noticed a lot of the same questions keep coming up
over and over.  Some of these questions are well answered by existing
documentation, but people have trouble finding it.  Others are not
answered, and still others are questions about integrating with common
tools and hosting platforms.

To help people find and discover this documentation, let's provide a FAQ
that covers common issues.  A lot of these issues are things I've seen
asked on Stack Overflow or elsewhere and we'd be doing everyone a
service if we included some stock answers in one place in our
documentation.

The FAQ is designed to be conversational, approachable, and geared
towards a competent novice user.  However, it also addresses questions
that I've seen from technically advanced colleagues.  I've tried to make
it address common questions about integrations with other tools, such as
CI systems and hosting platforms, without mentioning any specific tool
by name.  This keeps us neutral on particular tools, but recognizes that
these tools are a common part of people's development experiences.

I definitely think we'll add more questions as we go along, but this
seems like a reasonable start for now.  I'd love feedback about the
phrasing of questions or answers, anything I've missed, and anything
that might be technically inaccurate, especially about Windows.

brian m. carlson (1):
  docs: add a FAQ

 Documentation/Makefile   |   1 +
 Documentation/gitfaq.txt | 330 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 331 insertions(+)
 create mode 100644 Documentation/gitfaq.txt

[PATCH 1/1] docs: add a FAQ

[brian m. carlson]

Git is an enormously flexible and powerful piece of software.  However,
it can be intimidating for many users and there are a set of common
questions that users often ask.  While we already have some new user
documentation, it's worth adding a FAQ to address common questions that
users often have.  Even though some of this is addressed elsewhere in
the documentation, experience has shown that it is difficult for users
to find, so a centralized location is helpful.

Add such a FAQ and fill it with some common questions and answers.
While there are few entries now, we can expand it in the future to cover
more things as we find new questions that users have.  Let's also add
section markers so that people answering questions can directly link
users to the proper answer.

The FAQ also addresses common configuration questions that apply not
only to Git as an independent piece of software but also the ecosystem
of CI tools and hosting providers that people use, since these are the
source of common questions.  An attempt has been made to avoid
mentioning any particular provider or tool, but to nevertheless cover
common configurations that apply to a wide variety of such tools.

Note that the long lines for certain questions are required, since
Asciidoctor does not permit broken lines there.
---
 Documentation/Makefile   |   1 +
 Documentation/gitfaq.txt | 330 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 331 insertions(+)
 create mode 100644 Documentation/gitfaq.txt

diff --git a/Documentation/Makefile b/Documentation/Makefile
index 8fe829cc1b..59e6ce3a2a 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -30,6 +30,7 @@ MAN7_TXT += gitcredentials.txt
 MAN7_TXT += gitcvs-migration.txt
 MAN7_TXT += gitdiffcore.txt
 MAN7_TXT += giteveryday.txt
+MAN7_TXT += gitfaq.txt
 MAN7_TXT += gitglossary.txt
 MAN7_TXT += gitnamespaces.txt
 MAN7_TXT += gitremote-helpers.txt
diff --git a/Documentation/gitfaq.txt b/Documentation/gitfaq.txt
new file mode 100644
index 0000000000..318e4dd648
--- /dev/null
+++ b/Documentation/gitfaq.txt
@@ -0,0 +1,330 @@
+gitfaq(7)
+=========
+
+NAME
+----
+gitfaq - Frequently asked questions about using Git
+
+SYNOPSIS
+--------
+gitfaq
+
+DESCRIPTION
+-----------
+
+The examples in this FAQ assume a standard POSIX shell, like `bash` or `dash`,
+and a user, A U Thor, who has the account `author` on the hosting provider
+`git.example.org`.
+
+Configuration
+-------------
+
+[[user-name]]
+What should I put in `user.name`?::
+  You should put your personal name; that is, the name that other humans call
+	you.  This will be the name portion that is stored in every commit you make.
++
+This configuration doesn't have any effect on authenticating to remote
+services; for that, see `credential.username` in linkgit:git-config[1].
+
+[[http-postbuffer]]
+What does `http.postBuffer` really do?::
+	This option changes the size of the buffer that Git uses when pushing data to
+	a remote over HTTP or HTTPS.  If the data is larger than this size, libcurl,
+	which handles the HTTP support for Git, will use chunked transfer encoding
+	since it isn't known ahead of time what the size of the pushed data will be.
++
+Leaving this value at the default size is fine unless you know that either the
+remote server or a proxy in the middle doesn't support HTTP/1.1 (which
+introduced the chunked transfer encoding) or is known to be broken with chunked
+data.  People often suggest this as a solution for generic push problems, but
+since almost every server and proxy supports at least HTTP/1.1, raising this
+value usually doesn't solve most push problems.  A server or proxy that didn't
+correctly support HTTP/1.1 and chunked transfer encoding wouldn't be that useful
+on the Internet today, since it would break lots of traffic.
++
+Note that increasing this value will increase the memory used on every relevant
+push that Git does over HTTP or HTTPS, since the entire buffer is allocated
+regardless of whether or not it is all used.  Thus, it's best to leave it at the
+default unless you are sure you need a different value.
+
+[[configure-editor]]
+How do I configure a different editor?::
+	If you haven't specified an editor specifically for Git, it will by default
+	use the editor you've configured using the `VISUAL` or `EDITOR` environment
+	variables, or if neither is specified, the system default (which is usually
+	`vi`).  Since some people find `vi` difficult to use, it may be desirable to
+	change the editor used.
++
+If you want to configure a general editor for most programs which need one, you
+can edit your shell configuration (e.g., `~/.bashrc` or `~/.zshenv`) to contain
+a line setting the `EDITOR` or `VISUAL` environment variable to an appropriate
+value.  For example, if you preferred the editor `nano`, then you could write
+the following:
++
+----
+export VISUAL=nano
+----
++
+If you want to configure an editor specifically for Git, you can either set the
+`core.editor` configuration value or the `GIT_EDITOR` environment variable.  You
+can see linkgit:git-var[1] for details on the order in which these options are
+consulted.
++
+Note that in all cases, the editor value will be passed to the shell, so any
+arguments containing spaces should be appropriately quoted.  Additionally, if
+your editor normally detaches from the terminal when invoked, you should specify
+it with an argument that makes it not do that, or else Git will not see any
+changes.  An example of a configuration addressing both of these issues on
+Windows would be the configuration `"C:\Program Files\Vim\gvim.exe" --nofork`,
+which quotes the filename with spaces and specifies the `--nofork` option to
+avoid backgrounding the process.
+
+Credentials
+-----------
+
+[[http-credentials]]
+How do I specify my credentials when pushing over HTTP?::
+	The easiest way to do this is to use a credential helper via the
+	`credential.helper` configuration.  Most systems provide a standard choice to
+	integrate with the system credential manager.  For example, Git for Windows
+	provides the `wincred` credential manager, macOS has the `osxkeychain`
+	credential manager, and Unix systems with a standard desktop environment can
+	use the `libsecret` credential manager.  All of these store credentials in an
+	encrypted store to keep your passwords or tokens secure.
++
+In addition, you can use the `store` credential manager which stores in a file
+in your home directory, or the `cache` credential manager, which does not
+permanently store your credentials, but does prevent you from being prompted for
+them for a certain period of time.
++
+You can also just enter your password when prompted, or you can place the
+password (which must be percent-encoded) in the URL.  The latter option is not
+particularly secure and can lead to accidental exposure of credentials, so it is
+not recommended.
+
+[[http-credentials-environment]]
+How do I read a password or token from an environment variable?::
+  The `credential.helper` configuration option can also take an arbitrary shell
+	command that produces the credential protocol on standard output.  This is
+	useful when passing credentials into a container, for example.
++
+Such a shell command can be specified by starting the option value with an
+exclamation point.  If your password or token were stored in the `GIT_TOKEN`,
+you could run the following command to set your credential helper:
++
+----
+$ git config credential.helper \
+	'!f() { echo username=author; echo "password=$GIT_TOKEN"; };f'
+----
+
+[[http-reset-credentials]]
+How do I change the password or token I've saved in my credential manager?::
+	Usually, if the password or token is invalid, Git will erase it and prompt for
+	a new one.  However, there are times when this doesn't always happen.  To
+	change the password or token, you can erase the existing credentials and then
+	Git will prompt for new ones.  To erase credentials, use a syntax like the
+	following (substituting your username and the hostname):
++
+----
+$ echo url=https://author@git.example.org | git credential reject
+----
+
+[[multiple-accounts-http]]
+How do I use multiple accounts with the same hosting provider using HTTP?::
+  Usually the easiest way to distinguish between these accounts is to use the
+	username in the URL.  For example, if you have the accounts `author` and
+	`committer` on `git.example.org`, you can use the URLs
+	https://author@git.example.org/org1/project1.git and
+	https://committer@git.example.org/org2/project2.git.  This way, when you use a
+	credential helper, it will automatically try to look up the correct
+	credentials for your account.  If you already have a remote set up, you can
+	change the URL with something like `git remote set-url origin
+	https://author@git.example.org/org1/project1.git` (see linkgit:git-remote[1]
+	for details).
+
+[[multiple-accounts-ssh]]
+How do I use multiple accounts with the same hosting provider using SSH?::
+	With most hosting providers that support SSH, a single key pair uniquely
+	identifies a user.  Therefore, to use multiple accounts, it's necessary to
+	create a key pair for each account.  If you're using a reasonably modern
+	OpenSSH version, you can create a new key pair with something like `ssh-keygen
+	-t ed25519 -f ~/.ssh/id_committer`.  You can then register the public key (in
+	this case, `~/.ssh/id_committer.pub`; note the `.pub`) with the hosting
+	provider.
++
+Most hosting providers use a single SSH account for pushing; that is, all users
+push to the `git` account (e.g., `git@git.example.org`).  If that's the case for
+your provider, you can set up multiple aliases in SSH to make it clear which key
+pair to use.  For example, you could write something like the following,
+substituting the proper private key file:
++
+----
+# This is the account for author on git.example.org.
+Host example_author
+   HostName git.example.org
+	 User git
+	 # This is the key pair registered for author with git.example.org.
+	 IdentityFile ~/.ssh/id_author
+	 IdentitiesOnly yes
+# This is the committer for author on git.example.org.
+Host example_committer
+   HostName git.example.org
+	 User git
+	 # This is the key pair registered for committer with git.example.org.
+	 IdentityFile ~/.ssh/id_committer
+	 IdentitiesOnly yes
+----
++
+Then, you can adjust your push URL to use `git@example_author` or
+`git@example_committer` instead of `git@example.org` (e.g., `git remote set-url
+git@example_author:org1/project1.git`).
+
+Common Issues
+-------------
+
+[[last-commit-amend]]
+I've made a mistake in the last commit.  How do I change it?::
+	You can make the appropriate change to your working tree, run `git add <file>`
+	to stage it, and then `git commit --amend`.  Your change will be included in
+	the commit, and you'll be prompted to edit the commit message again; if you
+	don't want to edit it, you can use the `--no-edit` option to `git commit` in
+	addition, or just save and quit when your editor opens.
+
+[[undo-previous-change]]
+I've made a change with a bug and it's been included in the main branch.  How should I undo it?::
+	The usual way to deal with this is to use `git revert`.  This preserves the
+	history that the original change was made and was a valuable contribution, but
+	also introduces a new commit that undoes those changes because the original
+	had a problem.  The commit message of the revert indicates the commit which
+	was reverted and can be edited to include an explanation as to why the revert
+	was made.
+
+[[ignore-tracked-files]]
+How do I ignore changes to a tracked file?::
+  Git doesn't provide a way to do this.  The reason is that if Git needs to
+	overwrite this file, such as during a checkout, it doesn't know whether the
+	changes to the file are precious and should be kept, or whether they are
+	irrelevant and can safely be destroyed.  Therefore, it has to take the safe
+	route and always preserve them.
++
+Some people are tempted to use certain features of `git update-index`, namely
+the assume-unchanged and skip-worktree bits, but these don't work properly for
+this purpose and shouldn't be used this way.
++
+If your goal is to modify a configuration file, it can often be helpful to have
+a file checked into the repository which is a template or set of defaults which
+can then be copied alongside and modified as appropriate.  This second, modified
+file is usually ignored to prevent accidentally committing it.
+
+Hooks
+-----
+
+[[restrict-with-hooks]]
+How do I prevent users from making certain changes with hooks?::
+	The only safe place to make these changes is on the remote repository (i.e.,
+	the Git server), usually in the `pre-receive` hook or in a continuous
+	integration (CI) system.  These are the locations in which policy can be
+	enforced effectively.
++
+Some people try to use `pre-commit` hooks (or, for commit messages, `commit-msg`
+hooks) to check these things, which is fine if you're working as a solo
+developer and want the tooling to help you.  However, using hooks on a developer
+machine is not effective as a policy control because a user can bypass these
+hooks with `--no-verify` without being noticed (among various other ways).  Git
+assumes that the user is in control of their local repositories and doesn't try
+to prevent this or tattle on the user.
++
+In addition, some advanced users find `pre-commit` hooks to be an impediment to
+workflows that use temporary commits to stage work in progress or that create
+fixup commits, so it's better to push these kinds of checks to the server
+anyway.
+
+Cross-Platform Issues
+~~~~~~~~~~~~~~~~~~~~~
+
+[[windows-text-binary]]
+I'm on Windows and my text files are detected as binary.::
+	Git works best when you store text files as UTF-8.  Many programs on Windows
+	support UTF-8, but some do not and only use the little-endian UTF-16 format,
+	which Git detects as binary.  If you can't use UTF-8 with your programs, you
+	can specify a working tree encoding that indicates which encoding your files
+	should be checked out with, while still storing these files as UTF-8 in the
+	repository.  This allows tools like linkgit:git-diff[1] to work as expected,
+	while still allowing your tools to work.
++
+To do so, you can specify a linkgit:gitattributes[5] pattern with with the
+`working-tree-encoding` attribute.  For example, the following pattern sets all
+C files to use UTF-16LE-BOM, which is a common encoding on Windows:
++
+----
+*.c	working-tree-encoding=UTF-16LE-BOM
+----
++
+You will need to run `git add --renormalize` to have this take effect.  Note
+that if you are making these changes on a project that is used across platforms,
+you'll probably want to make it in a per-user configuration file or in the one
+in `$GIT_DIR/info/attributes`, since making it in a `.gitattributes` file in
+the repository will apply to all users of the repository.
++
+See the following entry for information about normalizing line endings as well,
+and see linkgit:gitattributes[5] for more information about attribute files.
+
+[[windows-diff-control-m]]
+I'm on Windows and git diff shows my files as having a `^M` at the end.::
+	By default, Git expects files to be stored with Unix line endings.  As such,
+	the carriage return (`^M`) that is part of a Windows line ending results is
+	show because it is considered to be trailing whitespace.  Git defaults to
+	showing trailing whitespace only on new lines, not existing ones.
++
+You can store the files in the repository with Unix line endings and convert
+them automatically to your platform's line endings.  To do that, set the
+configuration option `core.eol` to `native` and see the following entry for
+information about how to configure files as text or binary.
++
+You can also control this behavior with the `core.whitespace` setting if you
+don't wish to remove the carriage returns from your line endings.
+
+[[recommended-storage-settings]]
+What's the recommended way to store files in Git?::
+	While Git can store and handle any file of any type, there are some settings
+	that work better than others.  In general, we recommend that text files be
+	stored in UTF-8 without a byte-order mark (BOM) with LF (Unix-style) endings.
+	We also recommend the use of UTF-8 (again, without BOM) in commit messages.
+	These are the settings that work best across platforms and with tools such as
+	`git diff` and `git merge`.
++
+Additionally, if you have a choice between storage formats that are text based
+or non-text based, we recommend storing files in the text format and, if
+necessary, transforming them into the other format.  For example, a text-based
+SQL dump with one record per line will work much better for diffing and merging
+than an actual database file.  Similarly, text-based formats such as Markdown
+and AsciiDoc will work better than binary formats such as Microsoft Word and
+PDF.
++
+Similarly, storing binary dependencies (e.g., shared libraries or JAR files) or
+build products in the repository is generally not recommended.  Dependencies and
+build products are best stored on an artifact or package server with only
+references, URLs, and hashes stored in the repository.
++
+We also recommend setting a link:gitattributes[5] file to explicitly mark which
+files are text and which are binary.  If you want Git to guess, you can set the
+attribute `text=auto`.  For example, the following might be appropriate in some
+projects:
++
+----
+# By default, guess.
+*			text=auto
+# Mark all C files as text.
+*.c		text
+# Mark all JPEG files as binary.
+*.jpg	binary
+----
++
+These settings help tools pick the right format for output such as patches and
+result in files being checked out in the appropriate line ending for the
+platform.
+
+GIT
+---
+Part of the linkgit:git[1] suite

Re: [PATCH 1/1] docs: add a FAQ

[Junio C Hamano]

"brian m. carlson" <sandals@crustytoothpaste.net> writes:

> Note that the long lines for certain questions are required, since
> Asciidoctor does not permit broken lines there.

I didn't see "long lines", but was puzzled by a few lines with
ununiform indentation.

> +Configuration
> +-------------
> +
> +[[user-name]]
> +What should I put in `user.name`?::
> +  You should put your personal name; that is, the name that other humans call
> +	you.  This will be the name portion that is stored in every commit you make.

Shouldn't the first line "You should put ..." be indented to the
same level as the second line, like the entry for http-postbuffer we
see below?

> ++
> +This configuration doesn't have any effect on authenticating to remote
> +services; for that, see `credential.username` in linkgit:git-config[1].
> +
> +[[http-postbuffer]]
> +What does `http.postBuffer` really do?::
> +	This option changes the size of the buffer that Git uses when pushing data to
> +	a remote over HTTP or HTTPS.  If the data is larger than this size, libcurl,
> ...

> +[[http-credentials-environment]]
> +How do I read a password or token from an environment variable?::
> +  The `credential.helper` configuration option can also take an arbitrary shell

Likewise.

> +[[multiple-accounts-http]]
> +How do I use multiple accounts with the same hosting provider using HTTP?::
> +  Usually the easiest way to distinguish between these accounts is to use the

Likewise.

> +Most hosting providers use a single SSH account for pushing; that is, all users
> +push to the `git` account (e.g., `git@git.example.org`).  If that's the case for
> +your provider, you can set up multiple aliases in SSH to make it clear which key
> +pair to use.  For example, you could write something like the following,
> +substituting the proper private key file:
> ++
> +----
> +# This is the account for author on git.example.org.
> +Host example_author
> +   HostName git.example.org
> +	 User git

Here, shouldn't HostName entry be indented the same way as User and
other entries for this "Host" entry?

> +	 # This is the key pair registered for author with git.example.org.
> +	 IdentityFile ~/.ssh/id_author
> +	 IdentitiesOnly yes
> +# This is the committer for author on git.example.org.
> +Host example_committer
> +   HostName git.example.org

Likewise.

> +Common Issues
> +-------------
> +
> +[[last-commit-amend]]
> +I've made a mistake in the last commit.  How do I change it?::
> +	You can make the appropriate change to your working tree, run `git add <file>`
> +	to stage it, and then `git commit --amend`.  Your change will be included in
> +	the commit, and you'll be prompted to edit the commit message again; if you
> +	don't want to edit it, you can use the `--no-edit` option to `git commit` in
> +	addition, or just save and quit when your editor opens.

When the undesired part of the last change was "I added a junk
file", then instead of `git add`, `git rm [--cached]` would become
necessary.

I personally would prefer to say "if you want to use the original
commit message verbatim" instead of "you do not want to edit", but
it may be just me.  I just find the document to give more positive
attitude if it avoids phrasing end-users' wishes in terms of what
they do not want to do.

> +[[undo-previous-change]]
> +I've made a change with a bug and it's been included in the main branch.  How should I undo it?::
> +	The usual way to deal with this is to use `git revert`.  This preserves the
> +	history that the original change was made and was a valuable contribution, but
> +	also introduces a new commit that undoes those changes because the original
> +	had a problem.  The commit message of the revert indicates the commit which
> +	was reverted and can be edited to include an explanation as to why the revert
> +	was made.

Can we phrase "and can be edited" in a bit more opinionated way?
The users are encouraged to describe why and that is why we open an
editor by default for them to do so.

> +[[ignore-tracked-files]]
> +How do I ignore changes to a tracked file?::
> +  Git doesn't provide a way to do this.  The reason is that if Git needs to
> +	overwrite this file, such as during a checkout, it doesn't know whether the

Indentation.

> +----
> +# By default, guess.
> +*			text=auto
> +# Mark all C files as text.
> +*.c		text
> +# Mark all JPEG files as binary.
> +*.jpg	binary
> +----

The first entry text=auto is indented more deeply than others.  Intended?

Thanks.

Re: [PATCH 1/1] docs: add a FAQ

[brian m. carlson]

[-- Attachment #1: Type: text/plain, Size: 2587 bytes --]

On 2020-03-15 at 23:34:34, Junio C Hamano wrote:
> "brian m. carlson" <sandals@crustytoothpaste.net> writes:
> 
> > Note that the long lines for certain questions are required, since
> > Asciidoctor does not permit broken lines there.
> 
> I didn't see "long lines", but was puzzled by a few lines with
> ununiform indentation.

I'll fix all that.  Apparently somewhere along the line my editor got
confused and inserted two spaces (which is my typical AsciiDoc
configuration) instead of a tab (which is what I've configured for Git
files).

> > +Common Issues
> > +-------------
> > +
> > +[[last-commit-amend]]
> > +I've made a mistake in the last commit.  How do I change it?::
> > +	You can make the appropriate change to your working tree, run `git add <file>`
> > +	to stage it, and then `git commit --amend`.  Your change will be included in
> > +	the commit, and you'll be prompted to edit the commit message again; if you
> > +	don't want to edit it, you can use the `--no-edit` option to `git commit` in
> > +	addition, or just save and quit when your editor opens.
> 
> When the undesired part of the last change was "I added a junk
> file", then instead of `git add`, `git rm [--cached]` would become
> necessary.

Good point.  I'll mention `git add` or `git rm` as appropriate.

> I personally would prefer to say "if you want to use the original
> commit message verbatim" instead of "you do not want to edit", but
> it may be just me.  I just find the document to give more positive
> attitude if it avoids phrasing end-users' wishes in terms of what
> they do not want to do.

Thanks.  This is great feedback.

> > +[[undo-previous-change]]
> > +I've made a change with a bug and it's been included in the main branch.  How should I undo it?::
> > +	The usual way to deal with this is to use `git revert`.  This preserves the
> > +	history that the original change was made and was a valuable contribution, but
> > +	also introduces a new commit that undoes those changes because the original
> > +	had a problem.  The commit message of the revert indicates the commit which
> > +	was reverted and can be edited to include an explanation as to why the revert
> > +	was made.
> 
> Can we phrase "and can be edited" in a bit more opinionated way?
> The users are encouraged to describe why and that is why we open an
> editor by default for them to do so.

Yes, I agree that we want to encourage a helpful commit message here.  Will update.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 263 bytes --]

Re: [PATCH 1/1] docs: add a FAQ

[Emily Shaffer]

On Sun, Mar 15, 2020 at 10:39:23PM +0000, brian m. carlson wrote:
> Git is an enormously flexible and powerful piece of software.  However,
> it can be intimidating for many users and there are a set of common
> questions that users often ask.  While we already have some new user
> documentation, it's worth adding a FAQ to address common questions that
> users often have.  Even though some of this is addressed elsewhere in
> the documentation, experience has shown that it is difficult for users
> to find, so a centralized location is helpful.

It's true that some of it is duplicated; if we're worried about the info
getting out of sync, we might be able to do something like
Documentation/config so we're pulling in a single piece of text to both
places.

> 
> Add such a FAQ and fill it with some common questions and answers.
> While there are few entries now, we can expand it in the future to cover
> more things as we find new questions that users have.  Let's also add
> section markers so that people answering questions can directly link
> users to the proper answer.
> 
> The FAQ also addresses common configuration questions that apply not
> only to Git as an independent piece of software but also the ecosystem
> of CI tools and hosting providers that people use, since these are the
> source of common questions.  An attempt has been made to avoid
> mentioning any particular provider or tool, but to nevertheless cover
> common configurations that apply to a wide variety of such tools.
> 
> Note that the long lines for certain questions are required, since
> Asciidoctor does not permit broken lines there.
> ---
>  Documentation/Makefile   |   1 +
>  Documentation/gitfaq.txt | 330 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 331 insertions(+)
>  create mode 100644 Documentation/gitfaq.txt
> 
> diff --git a/Documentation/Makefile b/Documentation/Makefile
> index 8fe829cc1b..59e6ce3a2a 100644
> --- a/Documentation/Makefile
> +++ b/Documentation/Makefile
> @@ -30,6 +30,7 @@ MAN7_TXT += gitcredentials.txt
>  MAN7_TXT += gitcvs-migration.txt
>  MAN7_TXT += gitdiffcore.txt
>  MAN7_TXT += giteveryday.txt
> +MAN7_TXT += gitfaq.txt
>  MAN7_TXT += gitglossary.txt
>  MAN7_TXT += gitnamespaces.txt
>  MAN7_TXT += gitremote-helpers.txt
> diff --git a/Documentation/gitfaq.txt b/Documentation/gitfaq.txt
> new file mode 100644
> index 0000000000..318e4dd648
> --- /dev/null
> +++ b/Documentation/gitfaq.txt
> @@ -0,0 +1,330 @@
> +gitfaq(7)
> +=========
> +
> +NAME
> +----
> +gitfaq - Frequently asked questions about using Git
> +
> +SYNOPSIS
> +--------
> +gitfaq
> +
> +DESCRIPTION
> +-----------
> +
> +The examples in this FAQ assume a standard POSIX shell, like `bash` or `dash`,
> +and a user, A U Thor, who has the account `author` on the hosting provider
> +`git.example.org`.
> +
> +Configuration
> +-------------
> +
> +[[user-name]]
> +What should I put in `user.name`?::
> +  You should put your personal name; that is, the name that other humans call
> +	you.  This will be the name portion that is stored in every commit you make.

I like the direction but I think it is still a little unclear. Other
humans call me Emily, but I want to put "Emily Shaffer" in my user.name.
I wonder how we can suggest full name in a way that's as universal as
"the name that other humans call you"? I think I got around to this
point by using examples when covering the SOB in MyFirstContribution, so
I don't have a good answer off the top of my head.

> ++
> +This configuration doesn't have any effect on authenticating to remote
> +services; for that, see `credential.username` in linkgit:git-config[1].
> +
> +[[http-postbuffer]]
> +What does `http.postBuffer` really do?::
> +	This option changes the size of the buffer that Git uses when pushing data to
> +	a remote over HTTP or HTTPS.  If the data is larger than this size, libcurl,
> +	which handles the HTTP support for Git, will use chunked transfer encoding
> +	since it isn't known ahead of time what the size of the pushed data will be.
> ++
> +Leaving this value at the default size is fine unless you know that either the
> +remote server or a proxy in the middle doesn't support HTTP/1.1 (which
> +introduced the chunked transfer encoding) or is known to be broken with chunked
> +data.  People often suggest this as a solution for generic push problems, but
> +since almost every server and proxy supports at least HTTP/1.1, raising this
> +value usually doesn't solve most push problems.  A server or proxy that didn't

This might be burying the lede a little for someone frantically skimming
for an answer. If I was really spinning my wheels I might read "People
often suggest this as a solution for generic push problems" and go try
it. Is "People often (erroneously) suggest this ..." too verbose?

> +correctly support HTTP/1.1 and chunked transfer encoding wouldn't be that useful
> +on the Internet today, since it would break lots of traffic.
> ++
> +Note that increasing this value will increase the memory used on every relevant
> +push that Git does over HTTP or HTTPS, since the entire buffer is allocated
> +regardless of whether or not it is all used.  Thus, it's best to leave it at the
> +default unless you are sure you need a different value.
> +
> +[[configure-editor]]
> +How do I configure a different editor?::
> +	If you haven't specified an editor specifically for Git, it will by default
> +	use the editor you've configured using the `VISUAL` or `EDITOR` environment
> +	variables, or if neither is specified, the system default (which is usually
> +	`vi`).  Since some people find `vi` difficult to use, it may be desirable to
> +	change the editor used.
> ++
> +If you want to configure a general editor for most programs which need one, you
> +can edit your shell configuration (e.g., `~/.bashrc` or `~/.zshenv`) to contain
> +a line setting the `EDITOR` or `VISUAL` environment variable to an appropriate
> +value.  For example, if you preferred the editor `nano`, then you could write
> +the following:
> ++
> +----
> +export VISUAL=nano
> +----

I'll swallow my pride as a Vim user here and say that I think 'nano' is
a good choice to reference directly here; it seems to fit right into the
experience level this particular Q is targeting. Nice.

> ++
> +If you want to configure an editor specifically for Git, you can either set the
> +`core.editor` configuration value or the `GIT_EDITOR` environment variable.  You
> +can see linkgit:git-var[1] for details on the order in which these options are
> +consulted.
> ++
> +Note that in all cases, the editor value will be passed to the shell, so any
> +arguments containing spaces should be appropriately quoted.  Additionally, if
> +your editor normally detaches from the terminal when invoked, you should specify
> +it with an argument that makes it not do that, or else Git will not see any
> +changes.  An example of a configuration addressing both of these issues on
> +Windows would be the configuration `"C:\Program Files\Vim\gvim.exe" --nofork`,
> +which quotes the filename with spaces and specifies the `--nofork` option to
> +avoid backgrounding the process.
> +
> +Credentials
> +-----------
> +
> +[[http-credentials]]
> +How do I specify my credentials when pushing over HTTP?::
> +	The easiest way to do this is to use a credential helper via the
> +	`credential.helper` configuration.  Most systems provide a standard choice to
> +	integrate with the system credential manager.  For example, Git for Windows
> +	provides the `wincred` credential manager, macOS has the `osxkeychain`
> +	credential manager, and Unix systems with a standard desktop environment can
> +	use the `libsecret` credential manager.  All of these store credentials in an
> +	encrypted store to keep your passwords or tokens secure.
> ++
> +In addition, you can use the `store` credential manager which stores in a file
> +in your home directory, or the `cache` credential manager, which does not
> +permanently store your credentials, but does prevent you from being prompted for
> +them for a certain period of time.
> ++
> +You can also just enter your password when prompted, or you can place the
> +password (which must be percent-encoded) in the URL.  The latter option is not
> +particularly secure and can lead to accidental exposure of credentials, so it is
> +not recommended.
> +
> +[[http-credentials-environment]]
> +How do I read a password or token from an environment variable?::
> +  The `credential.helper` configuration option can also take an arbitrary shell
> +	command that produces the credential protocol on standard output.  This is
> +	useful when passing credentials into a container, for example.
> ++
> +Such a shell command can be specified by starting the option value with an
> +exclamation point.  If your password or token were stored in the `GIT_TOKEN`,
> +you could run the following command to set your credential helper:
> ++
> +----
> +$ git config credential.helper \
> +	'!f() { echo username=author; echo "password=$GIT_TOKEN"; };f'
> +----
> +
> +[[http-reset-credentials]]
> +How do I change the password or token I've saved in my credential manager?::
> +	Usually, if the password or token is invalid, Git will erase it and prompt for
> +	a new one.  However, there are times when this doesn't always happen.  To
> +	change the password or token, you can erase the existing credentials and then
> +	Git will prompt for new ones.  To erase credentials, use a syntax like the
> +	following (substituting your username and the hostname):
> ++
> +----
> +$ echo url=https://author@git.example.org | git credential reject
> +----
> +
> +[[multiple-accounts-http]]
> +How do I use multiple accounts with the same hosting provider using HTTP?::
> +  Usually the easiest way to distinguish between these accounts is to use the
> +	username in the URL.  For example, if you have the accounts `author` and
> +	`committer` on `git.example.org`, you can use the URLs
> +	https://author@git.example.org/org1/project1.git and
> +	https://committer@git.example.org/org2/project2.git.  This way, when you use a
> +	credential helper, it will automatically try to look up the correct
> +	credentials for your account.  If you already have a remote set up, you can
> +	change the URL with something like `git remote set-url origin
> +	https://author@git.example.org/org1/project1.git` (see linkgit:git-remote[1]
> +	for details).
> +
> +[[multiple-accounts-ssh]]
> +How do I use multiple accounts with the same hosting provider using SSH?::
> +	With most hosting providers that support SSH, a single key pair uniquely
> +	identifies a user.  Therefore, to use multiple accounts, it's necessary to
> +	create a key pair for each account.  If you're using a reasonably modern
> +	OpenSSH version, you can create a new key pair with something like `ssh-keygen
> +	-t ed25519 -f ~/.ssh/id_committer`.  You can then register the public key (in
> +	this case, `~/.ssh/id_committer.pub`; note the `.pub`) with the hosting
> +	provider.
> ++
> +Most hosting providers use a single SSH account for pushing; that is, all users
> +push to the `git` account (e.g., `git@git.example.org`).  If that's the case for
> +your provider, you can set up multiple aliases in SSH to make it clear which key
> +pair to use.  For example, you could write something like the following,
> +substituting the proper private key file:
> ++
> +----
> +# This is the account for author on git.example.org.
> +Host example_author
> +   HostName git.example.org
> +	 User git
> +	 # This is the key pair registered for author with git.example.org.
> +	 IdentityFile ~/.ssh/id_author
> +	 IdentitiesOnly yes
> +# This is the committer for author on git.example.org.
> +Host example_committer
> +   HostName git.example.org
> +	 User git
> +	 # This is the key pair registered for committer with git.example.org.
> +	 IdentityFile ~/.ssh/id_committer
> +	 IdentitiesOnly yes
> +----
> ++
> +Then, you can adjust your push URL to use `git@example_author` or
> +`git@example_committer` instead of `git@example.org` (e.g., `git remote set-url
> +git@example_author:org1/project1.git`).
> +
> +Common Issues
> +-------------
> +
> +[[last-commit-amend]]
> +I've made a mistake in the last commit.  How do I change it?::
> +	You can make the appropriate change to your working tree, run `git add <file>`
> +	to stage it, and then `git commit --amend`.  Your change will be included in
> +	the commit, and you'll be prompted to edit the commit message again; if you
> +	don't want to edit it, you can use the `--no-edit` option to `git commit` in
> +	addition, or just save and quit when your editor opens.
> +
> +[[undo-previous-change]]
> +I've made a change with a bug and it's been included in the main branch.  How should I undo it?::
> +	The usual way to deal with this is to use `git revert`.  This preserves the
> +	history that the original change was made and was a valuable contribution, but
> +	also introduces a new commit that undoes those changes because the original
> +	had a problem.  The commit message of the revert indicates the commit which
> +	was reverted and can be edited to include an explanation as to why the revert
> +	was made.
> +
> +[[ignore-tracked-files]]
> +How do I ignore changes to a tracked file?::
> +  Git doesn't provide a way to do this.  The reason is that if Git needs to
> +	overwrite this file, such as during a checkout, it doesn't know whether the
> +	changes to the file are precious and should be kept, or whether they are
> +	irrelevant and can safely be destroyed.  Therefore, it has to take the safe
> +	route and always preserve them.
> ++
> +Some people are tempted to use certain features of `git update-index`, namely
> +the assume-unchanged and skip-worktree bits, but these don't work properly for
> +this purpose and shouldn't be used this way.

Not really on topic for this particular paragraph, but there are a lot
of instances of "Some people ..." - in general, would it be less
combative to say something like "It's tempting to..." or "It might seem
like a good idea to..."? That way it feels less like "there are people
who do X and they are wrong" and more like "X might seem like a good
idea but it isn't". Or to put it another way, let's attack the bad idea,
not the people who suggest it.

> ++
> +If your goal is to modify a configuration file, it can often be helpful to have
> +a file checked into the repository which is a template or set of defaults which
> +can then be copied alongside and modified as appropriate.  This second, modified
> +file is usually ignored to prevent accidentally committing it.
> +
> +Hooks
> +-----
> +
> +[[restrict-with-hooks]]
> +How do I prevent users from making certain changes with hooks?::
> +	The only safe place to make these changes is on the remote repository (i.e.,
> +	the Git server), usually in the `pre-receive` hook or in a continuous
> +	integration (CI) system.  These are the locations in which policy can be
> +	enforced effectively.
> ++
> +Some people try to use `pre-commit` hooks (or, for commit messages, `commit-msg`
> +hooks) to check these things, which is fine if you're working as a solo
> +developer and want the tooling to help you.  However, using hooks on a developer
> +machine is not effective as a policy control because a user can bypass these
> +hooks with `--no-verify` without being noticed (among various other ways).  Git
> +assumes that the user is in control of their local repositories and doesn't try
> +to prevent this or tattle on the user.
> ++
> +In addition, some advanced users find `pre-commit` hooks to be an impediment to
> +workflows that use temporary commits to stage work in progress or that create
> +fixup commits, so it's better to push these kinds of checks to the server
> +anyway.
> +
> +Cross-Platform Issues
> +~~~~~~~~~~~~~~~~~~~~~
> +
> +[[windows-text-binary]]
> +I'm on Windows and my text files are detected as binary.::
> +	Git works best when you store text files as UTF-8.  Many programs on Windows
> +	support UTF-8, but some do not and only use the little-endian UTF-16 format,
> +	which Git detects as binary.  If you can't use UTF-8 with your programs, you
> +	can specify a working tree encoding that indicates which encoding your files
> +	should be checked out with, while still storing these files as UTF-8 in the
> +	repository.  This allows tools like linkgit:git-diff[1] to work as expected,
> +	while still allowing your tools to work.
> ++
> +To do so, you can specify a linkgit:gitattributes[5] pattern with with the
> +`working-tree-encoding` attribute.  For example, the following pattern sets all
> +C files to use UTF-16LE-BOM, which is a common encoding on Windows:
> ++
> +----
> +*.c	working-tree-encoding=UTF-16LE-BOM
> +----
> ++
> +You will need to run `git add --renormalize` to have this take effect.  Note
> +that if you are making these changes on a project that is used across platforms,
> +you'll probably want to make it in a per-user configuration file or in the one
> +in `$GIT_DIR/info/attributes`, since making it in a `.gitattributes` file in
> +the repository will apply to all users of the repository.
> ++
> +See the following entry for information about normalizing line endings as well,
> +and see linkgit:gitattributes[5] for more information about attribute files.
> +
> +[[windows-diff-control-m]]
> +I'm on Windows and git diff shows my files as having a `^M` at the end.::
> +	By default, Git expects files to be stored with Unix line endings.  As such,
> +	the carriage return (`^M`) that is part of a Windows line ending results is
> +	show because it is considered to be trailing whitespace.  Git defaults to
> +	showing trailing whitespace only on new lines, not existing ones.
> ++
> +You can store the files in the repository with Unix line endings and convert
> +them automatically to your platform's line endings.  To do that, set the
> +configuration option `core.eol` to `native` and see the following entry for
> +information about how to configure files as text or binary.
> ++
> +You can also control this behavior with the `core.whitespace` setting if you
> +don't wish to remove the carriage returns from your line endings.
> +
> +[[recommended-storage-settings]]
> +What's the recommended way to store files in Git?::
> +	While Git can store and handle any file of any type, there are some settings
> +	that work better than others.  In general, we recommend that text files be
> +	stored in UTF-8 without a byte-order mark (BOM) with LF (Unix-style) endings.
> +	We also recommend the use of UTF-8 (again, without BOM) in commit messages.
> +	These are the settings that work best across platforms and with tools such as
> +	`git diff` and `git merge`.
> ++
> +Additionally, if you have a choice between storage formats that are text based
> +or non-text based, we recommend storing files in the text format and, if
> +necessary, transforming them into the other format.  For example, a text-based
> +SQL dump with one record per line will work much better for diffing and merging
> +than an actual database file.  Similarly, text-based formats such as Markdown
> +and AsciiDoc will work better than binary formats such as Microsoft Word and
> +PDF.
> ++
> +Similarly, storing binary dependencies (e.g., shared libraries or JAR files) or
> +build products in the repository is generally not recommended.  Dependencies and
> +build products are best stored on an artifact or package server with only
> +references, URLs, and hashes stored in the repository.
> ++
> +We also recommend setting a link:gitattributes[5] file to explicitly mark which
> +files are text and which are binary.  If you want Git to guess, you can set the
> +attribute `text=auto`.  For example, the following might be appropriate in some
> +projects:
> ++
> +----
> +# By default, guess.
> +*			text=auto
> +# Mark all C files as text.
> +*.c		text
> +# Mark all JPEG files as binary.
> +*.jpg	binary
> +----
> ++
> +These settings help tools pick the right format for output such as patches and
> +result in files being checked out in the appropriate line ending for the
> +platform.
> +
> +GIT
> +---
> +Part of the linkgit:git[1] suite

Re: [PATCH 1/1] docs: add a FAQ

[Junio C Hamano]

Emily Shaffer <emilyshaffer@google.com> writes:

> Not really on topic for this particular paragraph, but there are a lot
> of instances of "Some people ..." - in general, would it be less
> combative to say something like "It's tempting to..." or "It might seem
> like a good idea to..."? That way it feels less like "there are people
> who do X and they are wrong" and more like "X might seem like a good
> idea but it isn't". Or to put it another way, let's attack the bad idea,
> not the people who suggest it.

Thanks for a perspective; I personally did not find that "Some
people do X" accuses them of doing it wrong, but you certainly
have a point.

Re: [PATCH 1/1] docs: add a FAQ

[brian m. carlson]

[-- Attachment #1: Type: text/plain, Size: 5770 bytes --]

On 2020-03-18 at 23:00:30, Emily Shaffer wrote:
> On Sun, Mar 15, 2020 at 10:39:23PM +0000, brian m. carlson wrote:
> > Git is an enormously flexible and powerful piece of software.  However,
> > it can be intimidating for many users and there are a set of common
> > questions that users often ask.  While we already have some new user
> > documentation, it's worth adding a FAQ to address common questions that
> > users often have.  Even though some of this is addressed elsewhere in
> > the documentation, experience has shown that it is difficult for users
> > to find, so a centralized location is helpful.
> 
> It's true that some of it is duplicated; if we're worried about the info
> getting out of sync, we might be able to do something like
> Documentation/config so we're pulling in a single piece of text to both
> places.

I'm not worried about this, since most of it has been this way for a
long time.

> > +[[user-name]]
> > +What should I put in `user.name`?::
> > +  You should put your personal name; that is, the name that other humans call
> > +	you.  This will be the name portion that is stored in every commit you make.
> 
> I like the direction but I think it is still a little unclear. Other
> humans call me Emily, but I want to put "Emily Shaffer" in my user.name.
> I wonder how we can suggest full name in a way that's as universal as
> "the name that other humans call you"? I think I got around to this
> point by using examples when covering the SOB in MyFirstContribution, so
> I don't have a good answer off the top of my head.

Yeah, this is tricky, since in many contexts the phrase "full name"
implies using the entirety of every part of your name, and most people
with middle names don't put them in the "user.name" entry.  Yet we want
it to be appropriate for people across a wide variety of cultures.

Maybe we should say something like this:

  You should put your personal name, generally a form using a given name
  and family name.  This will be the name portion that is stored in
  every commit you make.

Many cultures have a given name and a family name of some sort.  If we
wanted to provide an example, we could use Junio:

  For example, the current maintainer of Git uses "Junio C Hamano".

> > +[[http-postbuffer]]
> > +What does `http.postBuffer` really do?::
> > +	This option changes the size of the buffer that Git uses when pushing data to
> > +	a remote over HTTP or HTTPS.  If the data is larger than this size, libcurl,
> > +	which handles the HTTP support for Git, will use chunked transfer encoding
> > +	since it isn't known ahead of time what the size of the pushed data will be.
> > ++
> > +Leaving this value at the default size is fine unless you know that either the
> > +remote server or a proxy in the middle doesn't support HTTP/1.1 (which
> > +introduced the chunked transfer encoding) or is known to be broken with chunked
> > +data.  People often suggest this as a solution for generic push problems, but
> > +since almost every server and proxy supports at least HTTP/1.1, raising this
> > +value usually doesn't solve most push problems.  A server or proxy that didn't
> 
> This might be burying the lede a little for someone frantically skimming
> for an answer. If I was really spinning my wheels I might read "People
> often suggest this as a solution for generic push problems" and go try
> it. Is "People often (erroneously) suggest this ..." too verbose?

No, I think that's a good answer.

> > +If you want to configure a general editor for most programs which need one, you
> > +can edit your shell configuration (e.g., `~/.bashrc` or `~/.zshenv`) to contain
> > +a line setting the `EDITOR` or `VISUAL` environment variable to an appropriate
> > +value.  For example, if you preferred the editor `nano`, then you could write
> > +the following:
> > ++
> > +----
> > +export VISUAL=nano
> > +----
> 
> I'll swallow my pride as a Vim user here and say that I think 'nano' is
> a good choice to reference directly here; it seems to fit right into the
> experience level this particular Q is targeting. Nice.

I'm also a Vim user, but I took this idea from Debian, which uses the
options nano, nano-tiny, and vi (in that order) for its sensible-editor
utility if the user hasn't specified an editor any other way.  In any
event, the user can extrapolate from the example if nano isn't to their
tastes.

> > +[[ignore-tracked-files]]
> > +How do I ignore changes to a tracked file?::
> > +  Git doesn't provide a way to do this.  The reason is that if Git needs to
> > +	overwrite this file, such as during a checkout, it doesn't know whether the
> > +	changes to the file are precious and should be kept, or whether they are
> > +	irrelevant and can safely be destroyed.  Therefore, it has to take the safe
> > +	route and always preserve them.
> > ++
> > +Some people are tempted to use certain features of `git update-index`, namely
> > +the assume-unchanged and skip-worktree bits, but these don't work properly for
> > +this purpose and shouldn't be used this way.
> 
> Not really on topic for this particular paragraph, but there are a lot
> of instances of "Some people ..." - in general, would it be less
> combative to say something like "It's tempting to..." or "It might seem
> like a good idea to..."? That way it feels less like "there are people
> who do X and they are wrong" and more like "X might seem like a good
> idea but it isn't". Or to put it another way, let's attack the bad idea,
> not the people who suggest it.

Sure, I think that's a good idea.  Thanks for the suggestion.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 263 bytes --]

Re: [PATCH 1/1] docs: add a FAQ

[Shourya Shukla]

This seems like a really good idea! There are tons of redundant questions on StackOverflow
regarding Git in fact. One thing I want to ask, is that will this FAQ cover questions of the type:

"How do I change the remote of my repository?"
"What is the difference between a git merge and a git pull?"
"Git is tracking the files mentioned in .gitignore, what to do?"
"When do I rebase and when do I merge?"

And stuff like that. Basically questions which are more of a help to someone. Or are we focusing
only on the FAQs to kind of guide the user in Git, aiming to answer the fundamental questions and
not the general problems faced by a user?

Also, I had some FAQs in mind, can I add some into this?

I really appreciate your initiative! :)

Regards,
Shourya Shukla

Re: [PATCH 1/1] docs: add a FAQ

[brian m. carlson]

[-- Attachment #1: Type: text/plain, Size: 1612 bytes --]

On 2020-03-19 at 17:02:04, Shourya Shukla wrote:
> This seems like a really good idea! There are tons of redundant questions on StackOverflow
> regarding Git in fact. One thing I want to ask, is that will this FAQ cover questions of the type:
> 
> "How do I change the remote of my repository?"
> "What is the difference between a git merge and a git pull?"
> "Git is tracking the files mentioned in .gitignore, what to do?"
> "When do I rebase and when do I merge?"
> 
> And stuff like that. Basically questions which are more of a help to someone. Or are we focusing
> only on the FAQs to kind of guide the user in Git, aiming to answer the fundamental questions and
> not the general problems faced by a user?

I think these kinds of questions are good things to add.  I do see the
tracked-file-in-.gitignore question a lot in particular.

Part of my goal here is to address these kinds of questions in Git's
documentation itself.  If many people are asking the same question on
Stack Overflow, clearly there's confusion and we should address that by
making our documentation clearer and easier to find.

My hope is that folks will start linking to the FAQ once we have it up
on the website and it will become a good starting point for people to
find answers when they're unsure of something.

> Also, I had some FAQs in mind, can I add some into this?

I had always planned this patch as a start.  I fully expect that we'll
add more to it in the future, so I'd love to see additional
contributions.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 263 bytes --]