[PATCH] Document that using -M without other diff options is not a good idea

[PATCH] Document that using -M without other diff options is not a good idea

[Miklos Vajna]

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
---

I just noticed that I used 'git log -M' in some scripts which is obviously bad.
People should not use that option without other diff options.

 Documentation/diff-options.txt |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index b1f528a..ed827f8 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -92,7 +92,9 @@
 	Break complete rewrite changes into pairs of delete and create.
 
 -M::
-	Detect renames.
+	Detect renames. It's no good using this option if you don't use diff
+	options like `--name-status`, `-p` or `--stat` as it will just slow
+	down the revision walker.
 
 -C::
 	Detect copies as well as renames.  See also `--find-copies-harder`.
-- 
1.5.3.5

[PATCH] Include diff options in the git-log manpage

[Miklos Vajna]

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
---

Recently I wanted to see what git log -M does but actually I was not able to
find it in the manpage, finally figured out that all the diff options are
missing from here.

Removing -p as it's already in diff-options.txt.

If this patch OK, then I would like to send a similar patch to
git-rev-list.txt, too.

 Documentation/git-log.txt |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 5ec547c..4b1b982 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -27,6 +27,8 @@ OPTIONS
 
 include::pretty-options.txt[]
 
+include::diff-options.txt[]
+
 -<n>::
 	Limits the number of commits to show.
 
@@ -43,9 +45,6 @@ include::pretty-options.txt[]
 	commit.  This  option gives a better overview of the
 	evolution of a particular branch.
 
--p::
-	Show the change the commit introduces in a patch form.
-
 -g, \--walk-reflogs::
 	Show commits as they were recorded in the reflog. The log contains
 	a record about how the tip of a reference was changed.
-- 
1.5.3.5

Re: [PATCH] Document that using -M without other diff options is not a good idea

[Johannes Schindelin]

Hi,

On Thu, 1 Nov 2007, Miklos Vajna wrote:

> Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
> ---
> 
> I just noticed that I used 'git log -M' in some scripts which is obviously bad.
> People should not use that option without other diff options.
> 
>  Documentation/diff-options.txt |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
> index b1f528a..ed827f8 100644
> --- a/Documentation/diff-options.txt
> +++ b/Documentation/diff-options.txt
> @@ -92,7 +92,9 @@
>  	Break complete rewrite changes into pairs of delete and create.
>  
>  -M::
> -	Detect renames.
> +	Detect renames. It's no good using this option if you don't use diff
> +	options like `--name-status`, `-p` or `--stat` as it will just slow
> +	down the revision walker.

As I remarked on IRC earlier, this will also show up in the man page of 
git-diff, too.  Rather funny, no?

Ciao,
Dscho

Re: [PATCH] Document that using -M without other diff options is not a good idea

[Miklos Vajna]

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On Thu, Nov 01, 2007 at 03:09:25PM +0000, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> As I remarked on IRC earlier, this will also show up in the man page of 
> git-diff, too.  Rather funny, no?

ah, then i misunderstood you. so the correct way would be to juse ignore
the -M switch if it's useless? my problem is that if you use git log -M
then it's a pointless slowdown and you can't find this in the doc :s

thanks,
- VMiklos

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Re: [PATCH] Include diff options in the git-log manpage

[Miklos Vajna]

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On Thu, Nov 01, 2007 at 03:57:40PM +0100, Miklos Vajna <vmiklos@frugalware.org> wrote:
> Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
> ---
> 
> Recently I wanted to see what git log -M does but actually I was not able to
> find it in the manpage, finally figured out that all the diff options are
> missing from here.
> 
> Removing -p as it's already in diff-options.txt.
> 
> If this patch OK, then I would like to send a similar patch to
> git-rev-list.txt, too.
> 
>  Documentation/git-log.txt |    5 ++---
>  1 files changed, 2 insertions(+), 3 deletions(-)

could somebody please comment this patch? does it look ok?

thanks,
- VMiklos

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Re: [PATCH] Include diff options in the git-log manpage

[Miklos Vajna]

[-- Attachment #1: Type: text/plain, Size: 485 bytes --]

On Thu, Nov 01, 2007 at 03:57:40PM +0100, Miklos Vajna <vmiklos@frugalware.org> wrote:
> Recently I wanted to see what git log -M does but actually I was not able to
> find it in the manpage, finally figured out that all the diff options are
> missing from here.
> 
> Removing -p as it's already in diff-options.txt.

could you please have a look at this patch? this also fixes the "-C is
missing from man git-log" issue which was reported on IRC today.

thanks,
- VMiklos

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Re: [PATCH] Include diff options in the git-log manpage

[Junio C Hamano]

Miklos Vajna <vmiklos@frugalware.org> writes:

> On Thu, Nov 01, 2007 at 03:57:40PM +0100, Miklos Vajna <vmiklos@frugalware.org> wrote:
>> Recently I wanted to see what git log -M does but actually I was not able to
>> find it in the manpage, finally figured out that all the diff options are
>> missing from here.
>> 
>> Removing -p as it's already in diff-options.txt.
>
> could you please have a look at this patch? this also fixes the "-C is
> missing from man git-log" issue which was reported on IRC today.

There was a patch around diff options documentation from Sergei
last month, and somehow I thought it covered this issue as well.

Will format the docs before and after your fix, compare them, and then
decide either to drop or accept, which will take some time but will be
done before -rc0.

Thanks.

Re: [PATCH] Include diff options in the git-log manpage

[Junio C Hamano]

Miklos Vajna <vmiklos@frugalware.org> writes:

> On Thu, Nov 01, 2007 at 03:57:40PM +0100, Miklos Vajna <vmiklos@frugalware.org> wrote:
>> Recently I wanted to see what git log -M does but actually I was not able to
>> find it in the manpage, finally figured out that all the diff options are
>> missing from here.
>> 
>> Removing -p as it's already in diff-options.txt.
>
> could you please have a look at this patch? this also fixes the "-C is
> missing from man git-log" issue which was reported on IRC today.

Have you proofread the whole output after your patch?

 * It makes it say "--raw ... this is the default", while for "git log"
   no diff output is the default.

 * Also it says "-p ... (see section on generating patches)"; there is
   no such section.

This can be a possible fixup on top of your patch.  It has potential to
affect other documentation pages that includes the files touched.  I
have formatted log, diff and format-patch before your patch and after
your patch plus this patch, and eyeballed the difference, but please
double check.

---

 Documentation/diff-format.txt         |  159 +--------------------------------
 Documentation/diff-generate-patch.txt |  161 +++++++++++++++++++++++++++++++++
 Documentation/diff-options.txt        |    2 +
 Documentation/git-log.txt             |    2 +
 4 files changed, 166 insertions(+), 158 deletions(-)

diff --git a/Documentation/diff-format.txt b/Documentation/diff-format.txt
index 9709c35..2c3a4c4 100644
--- a/Documentation/diff-format.txt
+++ b/Documentation/diff-format.txt
@@ -83,161 +83,4 @@ Note that 'combined diff' lists only files which were modified from
 all parents.
 
 
-Generating patches with -p
---------------------------
-
-When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
-with a '-p' option, or "git diff" without the '--raw' option, they
-do not produce the output described above; instead they produce a
-patch file.  You can customize the creation of such patches via the
-GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables.
-
-What the -p option produces is slightly different from the traditional
-diff format.
-
-1.   It is preceded with a "git diff" header, that looks like
-     this:
-
-       diff --git a/file1 b/file2
-+
-The `a/` and `b/` filenames are the same unless rename/copy is
-involved.  Especially, even for a creation or a deletion,
-`/dev/null` is _not_ used in place of `a/` or `b/` filenames.
-+
-When rename/copy is involved, `file1` and `file2` show the
-name of the source file of the rename/copy and the name of
-the file that rename/copy produces, respectively.
-
-2.   It is followed by one or more extended header lines:
-
-       old mode <mode>
-       new mode <mode>
-       deleted file mode <mode>
-       new file mode <mode>
-       copy from <path>
-       copy to <path>
-       rename from <path>
-       rename to <path>
-       similarity index <number>
-       dissimilarity index <number>
-       index <hash>..<hash> <mode>
-
-3.  TAB, LF, double quote and backslash characters in pathnames
-    are represented as `\t`, `\n`, `\"` and `\\`, respectively.
-    If there is need for such substitution then the whole
-    pathname is put in double quotes.
-
-The similarity index is the percentage of unchanged lines, and
-the dissimilarity index is the percentage of changed lines.  It
-is a rounded down integer, followed by a percent sign.  The
-similarity index value of 100% is thus reserved for two equal
-files, while 100% dissimilarity means that no line from the old
-file made it into the new one.
-
-
-combined diff format
---------------------
-
-"git-diff-tree", "git-diff-files" and "git-diff" can take '-c' or
-'--cc' option to produce 'combined diff', which looks like this:
-
-------------
-diff --combined describe.c
-index fabadb8,cc95eb0..4866510
---- a/describe.c
-+++ b/describe.c
-@@@ -98,20 -98,12 +98,20 @@@
-	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
-  }
-
-- static void describe(char *arg)
- -static void describe(struct commit *cmit, int last_one)
-++static void describe(char *arg, int last_one)
-  {
- +	unsigned char sha1[20];
- +	struct commit *cmit;
-	struct commit_list *list;
-	static int initialized = 0;
-	struct commit_name *n;
-
- +	if (get_sha1(arg, sha1) < 0)
- +		usage(describe_usage);
- +	cmit = lookup_commit_reference(sha1);
- +	if (!cmit)
- +		usage(describe_usage);
- +
-	if (!initialized) {
-		initialized = 1;
-		for_each_ref(get_name);
-------------
-
-1.   It is preceded with a "git diff" header, that looks like
-     this (when '-c' option is used):
-
-       diff --combined file
-+
-or like this (when '--cc' option is used):
-
-       diff --c file
-
-2.   It is followed by one or more extended header lines
-     (this example shows a merge with two parents):
-
-       index <hash>,<hash>..<hash>
-       mode <mode>,<mode>..<mode>
-       new file mode <mode>
-       deleted file mode <mode>,<mode>
-+
-The `mode <mode>,<mode>..<mode>` line appears only if at least one of
-the <mode> is different from the rest. Extended headers with
-information about detected contents movement (renames and
-copying detection) are designed to work with diff of two
-<tree-ish> and are not used by combined diff format.
-
-3.   It is followed by two-line from-file/to-file header
-
-       --- a/file
-       +++ b/file
-+
-Similar to two-line header for traditional 'unified' diff
-format, `/dev/null` is used to signal created or deleted
-files.
-
-4.   Chunk header format is modified to prevent people from
-     accidentally feeding it to `patch -p1`. Combined diff format
-     was created for review of merge commit changes, and was not
-     meant for apply. The change is similar to the change in the
-     extended 'index' header:
-
-       @@@ <from-file-range> <from-file-range> <to-file-range> @@@
-+
-There are (number of parents + 1) `@` characters in the chunk
-header for combined diff format.
-
-Unlike the traditional 'unified' diff format, which shows two
-files A and B with a single column that has `-` (minus --
-appears in A but removed in B), `+` (plus -- missing in A but
-added to B), or `" "` (space -- unchanged) prefix, this format
-compares two or more files file1, file2,... with one file X, and
-shows how X differs from each of fileN.  One column for each of
-fileN is prepended to the output line to note how X's line is
-different from it.
-
-A `-` character in the column N means that the line appears in
-fileN but it does not appear in the result.  A `+` character
-in the column N means that the line appears in the last file,
-and fileN does not have that line (in other words, the line was
-added, from the point of view of that parent).
-
-In the above example output, the function signature was changed
-from both files (hence two `-` removals from both file1 and
-file2, plus `++` to mean one line that was added does not appear
-in either file1 nor file2).  Also two other lines are the same
-from file1 but do not appear in file2 (hence prefixed with ` +`).
-
-When shown by `git diff-tree -c`, it compares the parents of a
-merge commit with the merge result (i.e. file1..fileN are the
-parents).  When shown by `git diff-files -c`, it compares the
-two unresolved merge parents with the working tree file
-(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
-"their version").
+include::diff-generate-patch.txt[]
diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt
new file mode 100644
index 0000000..029c5f2
--- /dev/null
+++ b/Documentation/diff-generate-patch.txt
@@ -0,0 +1,161 @@
+Generating patches with -p
+--------------------------
+
+When "git-diff-index", "git-diff-tree", or "git-diff-files" are run
+with a '-p' option, "git diff" without the '--raw' option, or
+"git log" with the "-p" option, they
+do not produce the output described above; instead they produce a
+patch file.  You can customize the creation of such patches via the
+GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables.
+
+What the -p option produces is slightly different from the traditional
+diff format.
+
+1.   It is preceded with a "git diff" header, that looks like
+     this:
+
+       diff --git a/file1 b/file2
++
+The `a/` and `b/` filenames are the same unless rename/copy is
+involved.  Especially, even for a creation or a deletion,
+`/dev/null` is _not_ used in place of `a/` or `b/` filenames.
++
+When rename/copy is involved, `file1` and `file2` show the
+name of the source file of the rename/copy and the name of
+the file that rename/copy produces, respectively.
+
+2.   It is followed by one or more extended header lines:
+
+       old mode <mode>
+       new mode <mode>
+       deleted file mode <mode>
+       new file mode <mode>
+       copy from <path>
+       copy to <path>
+       rename from <path>
+       rename to <path>
+       similarity index <number>
+       dissimilarity index <number>
+       index <hash>..<hash> <mode>
+
+3.  TAB, LF, double quote and backslash characters in pathnames
+    are represented as `\t`, `\n`, `\"` and `\\`, respectively.
+    If there is need for such substitution then the whole
+    pathname is put in double quotes.
+
+The similarity index is the percentage of unchanged lines, and
+the dissimilarity index is the percentage of changed lines.  It
+is a rounded down integer, followed by a percent sign.  The
+similarity index value of 100% is thus reserved for two equal
+files, while 100% dissimilarity means that no line from the old
+file made it into the new one.
+
+
+combined diff format
+--------------------
+
+"git-diff-tree", "git-diff-files" and "git-diff" can take '-c' or
+'--cc' option to produce 'combined diff'.  For showing a merge commit
+with "git log -p", this is the default format.
+A 'combined diff' format looks like this:
+
+------------
+diff --combined describe.c
+index fabadb8,cc95eb0..4866510
+--- a/describe.c
++++ b/describe.c
+@@@ -98,20 -98,12 +98,20 @@@
+	return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
+  }
+
+- static void describe(char *arg)
+ -static void describe(struct commit *cmit, int last_one)
+++static void describe(char *arg, int last_one)
+  {
+ +	unsigned char sha1[20];
+ +	struct commit *cmit;
+	struct commit_list *list;
+	static int initialized = 0;
+	struct commit_name *n;
+
+ +	if (get_sha1(arg, sha1) < 0)
+ +		usage(describe_usage);
+ +	cmit = lookup_commit_reference(sha1);
+ +	if (!cmit)
+ +		usage(describe_usage);
+ +
+	if (!initialized) {
+		initialized = 1;
+		for_each_ref(get_name);
+------------
+
+1.   It is preceded with a "git diff" header, that looks like
+     this (when '-c' option is used):
+
+       diff --combined file
++
+or like this (when '--cc' option is used):
+
+       diff --c file
+
+2.   It is followed by one or more extended header lines
+     (this example shows a merge with two parents):
+
+       index <hash>,<hash>..<hash>
+       mode <mode>,<mode>..<mode>
+       new file mode <mode>
+       deleted file mode <mode>,<mode>
++
+The `mode <mode>,<mode>..<mode>` line appears only if at least one of
+the <mode> is different from the rest. Extended headers with
+information about detected contents movement (renames and
+copying detection) are designed to work with diff of two
+<tree-ish> and are not used by combined diff format.
+
+3.   It is followed by two-line from-file/to-file header
+
+       --- a/file
+       +++ b/file
++
+Similar to two-line header for traditional 'unified' diff
+format, `/dev/null` is used to signal created or deleted
+files.
+
+4.   Chunk header format is modified to prevent people from
+     accidentally feeding it to `patch -p1`. Combined diff format
+     was created for review of merge commit changes, and was not
+     meant for apply. The change is similar to the change in the
+     extended 'index' header:
+
+       @@@ <from-file-range> <from-file-range> <to-file-range> @@@
++
+There are (number of parents + 1) `@` characters in the chunk
+header for combined diff format.
+
+Unlike the traditional 'unified' diff format, which shows two
+files A and B with a single column that has `-` (minus --
+appears in A but removed in B), `+` (plus -- missing in A but
+added to B), or `" "` (space -- unchanged) prefix, this format
+compares two or more files file1, file2,... with one file X, and
+shows how X differs from each of fileN.  One column for each of
+fileN is prepended to the output line to note how X's line is
+different from it.
+
+A `-` character in the column N means that the line appears in
+fileN but it does not appear in the result.  A `+` character
+in the column N means that the line appears in the last file,
+and fileN does not have that line (in other words, the line was
+added, from the point of view of that parent).
+
+In the above example output, the function signature was changed
+from both files (hence two `-` removals from both file1 and
+file2, plus `++` to mean one line that was added does not appear
+in either file1 nor file2).  Also two other lines are the same
+from file1 but do not appear in file2 (hence prefixed with ` +`).
+
+When shown by `git diff-tree -c`, it compares the parents of a
+merge commit with the merge result (i.e. file1..fileN are the
+parents).  When shown by `git diff-files -c`, it compares the
+two unresolved merge parents with the working tree file
+(i.e. file1 is stage 2 aka "our version", file2 is stage 3 aka
+"their version").
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index e4af393..d0154bb 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -6,7 +6,9 @@
 
 ifndef::git-format-patch[]
 ifndef::git-diff[]
+ifndef::git-log[]
 :git-diff-core: 1
+endif::git-log[]
 endif::git-diff[]
 endif::git-format-patch[]
 
diff --git a/Documentation/git-log.txt b/Documentation/git-log.txt
index 4b1b982..5920d17 100644
--- a/Documentation/git-log.txt
+++ b/Documentation/git-log.txt
@@ -27,6 +27,7 @@ OPTIONS
 
 include::pretty-options.txt[]
 
+:git-log: 1
 include::diff-options.txt[]
 
 -<n>::
@@ -77,6 +78,7 @@ include::diff-options.txt[]
 
 include::pretty-formats.txt[]
 
+include::diff-generate-patch.txt[]
 
 Examples
 --------