[PATCH 0/16] fix config-reading in non-repos

[PATCH 0/16] fix config-reading in non-repos

[Jeff King]

The motivation for this series is to fix the regression in v2.9 where
core.logallrefupdates is sometimes not set properly in a newly
initialized repository, as described in this thread:

  http://public-inbox.org/git/c46d36ef-3c2e-374f-0f2e-ffe31104e023@gmx.de/T/#u

The root of the problem is that we are overly eager to read and use
config from ".git/config", even when we have not established that it is
part of a repository. This is especially bad for git-init, which would
not want to read anything until we've created the new repo.

So the two interesting parts of the fix are:

  1. We stop blindly reading ".git/config" when we don't know there's an
     actual git directory. This is in patch 14, and is actually enough
     to fix the v2.9 regression.

  2. We are more thorough about dropping any cached config values when
     we move into the new repository in git-init (patch 16).

     I didn't dig into when this was broken, but it was probably when we
     switched git_config() to use cached values in the v2.2.0
     time-frame.

Doing (1) required fixing up some builtins that depended on the blind
.git/config thing, as the tests demonstrated. But I think this is a sign
that we are moving in the right direction, because each one of those
programs could easily be demonstrated to be broken in scenarios only
slightly more exotic than the test scripts (e.g., see patch 3 for one of
the simplest cases).

So I think notwithstanding their use as prep for patch 14, patches 1-13
fix useful bugs.

I won't be surprised if there are other fallouts that were not caught by
the test suite (i.e., programs that expect to read config, don't do
RUN_SETUP, but aren't covered well by tests). I poked around the list of
builtins in git.c that do not use RUN_SETUP, and they seem to correctly
end up in setup_git_directory_gently() before reading config. But it's
possible I missed a case.

So this is definitely a bit larger than I'd hope for a regression-fix to
maint. But anything that doesn't address this issue at the config layer
is going to end up as a bit of a hack, and I'd rather not pile up hacks
if we can avoid it.

I have a few patches on top that go even further and disallow the
auto-fallback of looking in ".git" at all for non-repositories. I think
that's the right thing to do, and after years of chipping away at the
setup code, I think we're finally at a point to make that change (with a
few fixes of course). But that's an even riskier change and not fixing
an immediate regression. So I'll hold that back for now, and hopefully
it would become "master" material once this is sorted out.

I've cc'd Dennis, who helped investigate solutions in the thread
mentioned above, and Duy, because historically he has been the one most
willing and able to battle the dragon of our setup code. :)

  [01/16]: t1007: factor out repeated setup
  [02/16]: hash-object: always try to set up the git repository
  [03/16]: patch-id: use RUN_SETUP_GENTLY
  [04/16]: diff: skip implicit no-index check when given --no-index
  [05/16]: diff: handle --no-index prefixes consistently
  [06/16]: diff: always try to set up the repository
  [07/16]: pager: remove obsolete comment
  [08/16]: pager: stop loading git_default_config()
  [09/16]: pager: make pager_program a file-local static
  [10/16]: pager: use callbacks instead of configset
  [11/16]: pager: handle early config
  [12/16]: t1302: use "git -C"
  [13/16]: test-config: setup git directory
  [14/16]: config: only read .git/config from configured repos
  [15/16]: init: expand comments explaining config trickery
  [16/16]: init: reset cached config when entering new repo

-Peff

[PATCH 01/16] t1007: factor out repeated setup

[Jeff King]

We have a series of 3 CRLF tests that do exactly the same
(long) setup sequence. Let's pull it out into a common setup
test, which is shorter, more efficient, and will make it
easier to add new tests.

Note that we don't have to worry about cleaning up any of
the setup which was previously per-test; we call pop_repo
after the CRLF tests, which cleans up everything.

Signed-off-by: Jeff King <peff@peff.net>
---
 t/t1007-hash-object.sh | 32 ++++++++------------------------
 1 file changed, 8 insertions(+), 24 deletions(-)

diff --git a/t/t1007-hash-object.sh b/t/t1007-hash-object.sh
index 7d2baa1..c89faa6 100755
--- a/t/t1007-hash-object.sh
+++ b/t/t1007-hash-object.sh
@@ -101,7 +101,7 @@ test_expect_success 'git hash-object --stdin file1 <file0 first operates on file
 	test "$obname1" = "$obname1new"
 '
 
-test_expect_success 'check that appropriate filter is invoke when --path is used' '
+test_expect_success 'set up crlf tests' '
 	echo fooQ | tr Q "\\015" >file0 &&
 	cp file0 file1 &&
 	echo "file0 -crlf" >.gitattributes &&
@@ -109,7 +109,10 @@ test_expect_success 'check that appropriate filter is invoke when --path is used
 	git config core.autocrlf true &&
 	file0_sha=$(git hash-object file0) &&
 	file1_sha=$(git hash-object file1) &&
-	test "$file0_sha" != "$file1_sha" &&
+	test "$file0_sha" != "$file1_sha"
+'
+
+test_expect_success 'check that appropriate filter is invoke when --path is used' '
 	path1_sha=$(git hash-object --path=file1 file0) &&
 	path0_sha=$(git hash-object --path=file0 file1) &&
 	test "$file0_sha" = "$path0_sha" &&
@@ -117,38 +120,19 @@ test_expect_success 'check that appropriate filter is invoke when --path is used
 	path1_sha=$(cat file0 | git hash-object --path=file1 --stdin) &&
 	path0_sha=$(cat file1 | git hash-object --path=file0 --stdin) &&
 	test "$file0_sha" = "$path0_sha" &&
-	test "$file1_sha" = "$path1_sha" &&
-	git config --unset core.autocrlf
+	test "$file1_sha" = "$path1_sha"
 '
 
 test_expect_success 'check that --no-filters option works' '
-	echo fooQ | tr Q "\\015" >file0 &&
-	cp file0 file1 &&
-	echo "file0 -crlf" >.gitattributes &&
-	echo "file1 crlf" >>.gitattributes &&
-	git config core.autocrlf true &&
-	file0_sha=$(git hash-object file0) &&
-	file1_sha=$(git hash-object file1) &&
-	test "$file0_sha" != "$file1_sha" &&
 	nofilters_file1=$(git hash-object --no-filters file1) &&
 	test "$file0_sha" = "$nofilters_file1" &&
 	nofilters_file1=$(cat file1 | git hash-object --stdin) &&
-	test "$file0_sha" = "$nofilters_file1" &&
-	git config --unset core.autocrlf
+	test "$file0_sha" = "$nofilters_file1"
 '
 
 test_expect_success 'check that --no-filters option works with --stdin-paths' '
-	echo fooQ | tr Q "\\015" >file0 &&
-	cp file0 file1 &&
-	echo "file0 -crlf" >.gitattributes &&
-	echo "file1 crlf" >>.gitattributes &&
-	git config core.autocrlf true &&
-	file0_sha=$(git hash-object file0) &&
-	file1_sha=$(git hash-object file1) &&
-	test "$file0_sha" != "$file1_sha" &&
 	nofilters_file1=$(echo "file1" | git hash-object --stdin-paths --no-filters) &&
-	test "$file0_sha" = "$nofilters_file1" &&
-	git config --unset core.autocrlf
+	test "$file0_sha" = "$nofilters_file1"
 '
 
 pop_repo
-- 
2.10.0.230.g6f8d04b

[PATCH 02/16] hash-object: always try to set up the git repository

[Jeff King]

When "hash-object" is run without "-w", we don't need to be
in a git repository at all; we can just hash the object and
write its sha1 to stdout. However, if we _are_ in a git
repository, we would want to know that so we can follow the
normal rules for respecting config, .gitattributes, etc.

This happens to work at the top-level of a git repository
because we blindly read ".git/config", but as the included
test shows, it does not work when you are in a subdirectory.

The solution is to just do a "gentle" setup in this case. We
already take care to use prefix_filename() on any filename
arguments we get (to handle the "-w" case), so we don't need
to do anything extra to handle the side effects of repo
setup.

An alternative would be to specify RUN_SETUP_GENTLY for this
command in git.c, and then die if "-w" is set but we are not
in a repository. However, the error messages generated at
the time of setup_git_directory() are more detailed, so it's
better to find out which mode we are in, and then call the
appropriate function.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/hash-object.c  | 13 ++++++++-----
 t/t1007-hash-object.sh | 11 +++++++++++
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/builtin/hash-object.c b/builtin/hash-object.c
index f7d3567..9028e1f 100644
--- a/builtin/hash-object.c
+++ b/builtin/hash-object.c
@@ -87,6 +87,7 @@ int cmd_hash_object(int argc, const char **argv, const char *prefix)
 	int stdin_paths = 0;
 	int no_filters = 0;
 	int literally = 0;
+	int nongit = 0;
 	unsigned flags = HASH_FORMAT_CHECK;
 	const char *vpath = NULL;
 	const struct option hash_object_options[] = {
@@ -107,12 +108,14 @@ int cmd_hash_object(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, NULL, hash_object_options,
 			     hash_object_usage, 0);
 
-	if (flags & HASH_WRITE_OBJECT) {
+	if (flags & HASH_WRITE_OBJECT)
 		prefix = setup_git_directory();
-		prefix_length = prefix ? strlen(prefix) : 0;
-		if (vpath && prefix)
-			vpath = prefix_filename(prefix, prefix_length, vpath);
-	}
+	else
+		prefix = setup_git_directory_gently(&nongit);
+
+	prefix_length = prefix ? strlen(prefix) : 0;
+	if (vpath && prefix)
+		vpath = prefix_filename(prefix, prefix_length, vpath);
 
 	git_config(git_default_config, NULL);
 
diff --git a/t/t1007-hash-object.sh b/t/t1007-hash-object.sh
index c89faa6..acca9ac 100755
--- a/t/t1007-hash-object.sh
+++ b/t/t1007-hash-object.sh
@@ -123,6 +123,17 @@ test_expect_success 'check that appropriate filter is invoke when --path is used
 	test "$file1_sha" = "$path1_sha"
 '
 
+test_expect_success 'gitattributes also work in a subdirectory' '
+	mkdir subdir &&
+	(
+		cd subdir &&
+		subdir_sha0=$(git hash-object ../file0) &&
+		subdir_sha1=$(git hash-object ../file1) &&
+		test "$file0_sha" = "$subdir_sha0" &&
+		test "$file1_sha" = "$subdir_sha1"
+	)
+'
+
 test_expect_success 'check that --no-filters option works' '
 	nofilters_file1=$(git hash-object --no-filters file1) &&
 	test "$file0_sha" = "$nofilters_file1" &&
-- 
2.10.0.230.g6f8d04b

[PATCH 03/16] patch-id: use RUN_SETUP_GENTLY

[Jeff King]

Patch-id does not require a repository because it is just
processing the incoming diff on stdin, but it may look at
git config for keys like patchid.stable.

Even though we do not setup_git_directory(), this works from
the top-level of a repository because we blindly look at
".git/config" in this case. But as the included test
demonstrates, it does not work from a subdirectory.

We can fix it by using RUN_SETUP_GENTLY. We do not take any
filenames from the user on the command line, so there's no
need to adjust them via prefix_filename().

Signed-off-by: Jeff King <peff@peff.net>
---
 git.c               |  2 +-
 t/t4204-patch-id.sh | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/git.c b/git.c
index 1c61151..ab5c99c 100644
--- a/git.c
+++ b/git.c
@@ -444,7 +444,7 @@ static struct cmd_struct commands[] = {
 	{ "pack-objects", cmd_pack_objects, RUN_SETUP },
 	{ "pack-redundant", cmd_pack_redundant, RUN_SETUP },
 	{ "pack-refs", cmd_pack_refs, RUN_SETUP },
-	{ "patch-id", cmd_patch_id },
+	{ "patch-id", cmd_patch_id, RUN_SETUP_GENTLY },
 	{ "pickaxe", cmd_blame, RUN_SETUP },
 	{ "prune", cmd_prune, RUN_SETUP },
 	{ "prune-packed", cmd_prune_packed, RUN_SETUP },
diff --git a/t/t4204-patch-id.sh b/t/t4204-patch-id.sh
index 84a8096..0288c17 100755
--- a/t/t4204-patch-id.sh
+++ b/t/t4204-patch-id.sh
@@ -143,6 +143,20 @@ test_expect_success 'patch-id supports git-format-patch MIME output' '
 	test_cmp patch-id_master patch-id_same
 '
 
+test_expect_success 'patch-id respects config from subdir' '
+	test_config patchid.stable true &&
+	mkdir subdir &&
+
+	# copy these because test_patch_id() looks for them in
+	# the current directory
+	cp bar-then-foo foo-then-bar subdir &&
+
+	(
+		cd subdir &&
+		test_patch_id irrelevant patchid.stable=true
+	)
+'
+
 cat >nonl <<\EOF
 diff --git i/a w/a
 index e69de29..2e65efe 100644
-- 
2.10.0.230.g6f8d04b

[PATCH 04/16] diff: skip implicit no-index check when given --no-index

[Jeff King]

We can invoke no-index mode in two ways: by an explicit
request from the user, or implicitly by noticing that we
have two paths, and at least one is outside the repository.

If the user already told us --no-index, there is no need for
us to do the implicit test at all.  However, we currently
do, and downgrade our "explicit" to DIFF_NO_INDEX_IMPLICIT.

This doesn't have any user-visible behavior, though it's not
immediately obvious why. We only trigger the implicit check
when we have exactly two non-option arguments. And the only
code that cares about implicit versus explicit is an error
message that we show when we _don't_ have two non-option
arguments.

However, it's worth fixing anyway. Besides being slightly
more efficient, it makes the code easier to follow, which
will help when we modify it in future patches.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/diff.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/builtin/diff.c b/builtin/diff.c
index b7a9405..a31643c 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -301,20 +301,21 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 			break;
 	}
 
-	if (!no_index)
+	if (!no_index) {
 		prefix = setup_git_directory_gently(&nongit);
 
-	/*
-	 * Treat git diff with at least one path outside of the
-	 * repo the same as if the command would have been executed
-	 * outside of a git repository.  In this case it behaves
-	 * the same way as "git diff --no-index <a> <b>", which acts
-	 * as a colourful "diff" replacement.
-	 */
-	if (nongit || ((argc == i + 2) &&
-		       (!path_inside_repo(prefix, argv[i]) ||
-			!path_inside_repo(prefix, argv[i + 1]))))
-		no_index = DIFF_NO_INDEX_IMPLICIT;
+		/*
+		 * Treat git diff with at least one path outside of the
+		 * repo the same as if the command would have been executed
+		 * outside of a git repository.  In this case it behaves
+		 * the same way as "git diff --no-index <a> <b>", which acts
+		 * as a colourful "diff" replacement.
+		 */
+		if (nongit || ((argc == i + 2) &&
+			       (!path_inside_repo(prefix, argv[i]) ||
+				!path_inside_repo(prefix, argv[i + 1]))))
+			no_index = DIFF_NO_INDEX_IMPLICIT;
+	}
 
 	if (!no_index)
 		gitmodules_config();
-- 
2.10.0.230.g6f8d04b

[PATCH 05/16] diff: handle --no-index prefixes consistently

[Jeff King]

If we see an explicit "git diff --no-index ../foo ../bar",
then we do not set up the git repository at all (we already
know we are in --no-index mode, so do not have to check "are
we in a repository?"), and hence have no "prefix" within the
repository. A patch generated by this command will have the
filenames "a/../foo" and "b/../bar", no matter which
directory we are in with respect to any repository.

However, in the implicit case, where we notice that the
files are outside the repository, we will have chdir()'d to
the top-level of the repository. We then feed the prefix
back to the diff machinery. As a result, running the same
diff from a subdirectory will result in paths that look like
"a/subdir/../../foo".

Besides being unnecessarily long, this may also be confusing
to the user: they don't care about the subdir or the
repository at all; it's just where they happened to be when
running the command. We should treat this the same as the
explicit --no-index case.

One way to address this would be to chdir() back to the
original path before running our diff. However, that's a bit
hacky, as we would also need to adjust $GIT_DIR, which could
be a relative path from our top-level.

Instead, we can reuse the diff machinery's RELATIVE_NAME
option, which automatically strips off the prefix. Note that
this _also_ restricts the diff to this relative prefix, but
that's OK for our purposes: we queue our own diff pairs
manually, and do not rely on that part of the diff code.

Signed-off-by: Jeff King <peff@peff.net>
---
 diff-no-index.c          |  3 +++
 t/t4053-diff-no-index.sh | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/diff-no-index.c b/diff-no-index.c
index 1f8999b..f420786 100644
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -281,6 +281,9 @@ void diff_no_index(struct rev_info *revs,
 
 	DIFF_OPT_SET(&revs->diffopt, NO_INDEX);
 
+	DIFF_OPT_SET(&revs->diffopt, RELATIVE_NAME);
+	revs->diffopt.prefix = prefix;
+
 	revs->max_count = -2;
 	diff_setup_done(&revs->diffopt);
 
diff --git a/t/t4053-diff-no-index.sh b/t/t4053-diff-no-index.sh
index 6eb8321..e60c951 100755
--- a/t/t4053-diff-no-index.sh
+++ b/t/t4053-diff-no-index.sh
@@ -89,4 +89,22 @@ test_expect_success 'turning a file into a directory' '
 	)
 '
 
+test_expect_success 'diff from repo subdir shows real paths (explicit)' '
+	echo "diff --git a/../../non/git/a b/../../non/git/b" >expect &&
+	test_expect_code 1 \
+		git -C repo/sub \
+		diff --no-index ../../non/git/a ../../non/git/b >actual &&
+	head -n 1 <actual >actual.head &&
+	test_cmp expect actual.head
+'
+
+test_expect_success 'diff from repo subdir shows real paths (implicit)' '
+	echo "diff --git a/../../non/git/a b/../../non/git/b" >expect &&
+	test_expect_code 1 \
+		git -C repo/sub \
+		diff ../../non/git/a ../../non/git/b >actual &&
+	head -n 1 <actual >actual.head &&
+	test_cmp expect actual.head
+'
+
 test_done
-- 
2.10.0.230.g6f8d04b

[PATCH 06/16] diff: always try to set up the repository

[Jeff King]

If we see an explicit "--no-index", we do not bother calling
setup_git_directory_gently() at all. This means that we may
miss out on reading repo-specific config.

It's arguable whether this is correct or not. If we were
designing from scratch, making "git diff --no-index"
completely ignore the repository makes some sense. But we
are nowhere near scratch, so let's look at the existing
behavior:

  1. If you're in the top-level of a repository and run an
     explicit "diff --no-index", the config subsystem falls
     back to reading ".git/config", and we will respect repo
     config.

  2. If you're in a subdirectory of a repository, then we
     still try to read ".git/config", but it generally
     doesn't exist. So "diff --no-index" there does not
     respect repo config.

  3. If you have $GIT_DIR set in the environment, we read
     and respect $GIT_DIR/config,

  4. If you run "git diff /tmp/foo /tmp/bar" to get an
     implicit no-index, we _do_ run the repository setup,
     and set $GIT_DIR (or respect an existing $GIT_DIR
     variable). We find the repo config no matter where we
     started, and respect it.

So we already respect the repository config in a number of
common cases, and case (2) is the only one that does not.
And at least one of our tests, t4034, depends on case (1)
behaving as it does now (though it is just incidental, not
an explicit test for this behavior).

So let's bring case (2) in line with the others by always
running the repository setup, even with an explicit
"--no-index". We shouldn't need to change anything else, as the
implicit case already handles the prefix.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/diff.c           |  4 ++--
 t/t4053-diff-no-index.sh | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/builtin/diff.c b/builtin/diff.c
index a31643c..7f91f6d 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -301,9 +301,9 @@ int cmd_diff(int argc, const char **argv, const char *prefix)
 			break;
 	}
 
-	if (!no_index) {
-		prefix = setup_git_directory_gently(&nongit);
+	prefix = setup_git_directory_gently(&nongit);
 
+	if (!no_index) {
 		/*
 		 * Treat git diff with at least one path outside of the
 		 * repo the same as if the command would have been executed
diff --git a/t/t4053-diff-no-index.sh b/t/t4053-diff-no-index.sh
index e60c951..453e6c3 100755
--- a/t/t4053-diff-no-index.sh
+++ b/t/t4053-diff-no-index.sh
@@ -107,4 +107,24 @@ test_expect_success 'diff from repo subdir shows real paths (implicit)' '
 	test_cmp expect actual.head
 '
 
+test_expect_success 'diff --no-index from repo subdir respects config (explicit)' '
+	echo "diff --git ../../non/git/a ../../non/git/b" >expect &&
+	test_config -C repo diff.noprefix true &&
+	test_expect_code 1 \
+		git -C repo/sub \
+		diff --no-index ../../non/git/a ../../non/git/b >actual &&
+	head -n 1 <actual >actual.head &&
+	test_cmp expect actual.head
+'
+
+test_expect_success 'diff --no-index from repo subdir respects config (implicit)' '
+	echo "diff --git ../../non/git/a ../../non/git/b" >expect &&
+	test_config -C repo diff.noprefix true &&
+	test_expect_code 1 \
+		git -C repo/sub \
+		diff ../../non/git/a ../../non/git/b >actual &&
+	head -n 1 <actual >actual.head &&
+	test_cmp expect actual.head
+'
+
 test_done
-- 
2.10.0.230.g6f8d04b

[PATCH 07/16] pager: remove obsolete comment

[Jeff King]

The comment at the top of pager.c claims that we've split
the code out so that Windows can do something different.
This dates back to f67b45f (Introduce trivial new pager.c
helper infrastructure, 2006-02-28), because the original
implementation used fork(). Later, we ended up sticking the
Windows #ifdefs into this file anyway. And then even later,
in ea27a18 (spawn pager via run_command interface,
2008-07-22) we unified the implementations.

So these days this comment is really saying nothing at all.
Let's drop it.

Signed-off-by: Jeff King <peff@peff.net>
---
 pager.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/pager.c b/pager.c
index 6470b81..ae46da9 100644
--- a/pager.c
+++ b/pager.c
@@ -6,11 +6,6 @@
 #define DEFAULT_PAGER "less"
 #endif
 
-/*
- * This is split up from the rest of git so that we can do
- * something different on Windows.
- */
-
 static struct child_process pager_process = CHILD_PROCESS_INIT;
 
 static void wait_for_pager(int in_signal)
-- 
2.10.0.230.g6f8d04b

[PATCH 08/16] pager: stop loading git_default_config()

[Jeff King]

In git_pager(), we really only care about getting the value
of core.pager. But to do so, we use the git_default_config()
callback, which loads many other values. Ordinarily it
isn't a big deal to load this config an extra time, as it
simply overwrites the values from the previous run. But it's
a bad idea here, for two reasons:

  1. The pager setup may be called very early in the
     program, before we have found the git repository. As a
     result, we may fail to read the correct repo-level
     config file.  This is a problem for core.pager, too,
     but we should at least try to minimize the pollution to
     other configured values.

  2. Because we call setup_pager() from git.c, basically
     every builtin command _may_ end up reading this config
     and getting an implicit git_default_config() setup.

     Which doesn't sound like a terrible thing, except that
     we don't do it consistently; it triggers only when
     stdout is a tty. So if a command forgets to load the
     default config itself (but depends on it anyway), it
     may appear to work, and then mysteriously fail when the
     pager is not in use.

We can improve this by loading _just_ the core.pager config
from git_pager().

Signed-off-by: Jeff King <peff@peff.net>
---
 config.c | 3 ---
 pager.c  | 9 ++++++++-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/config.c b/config.c
index 0dfed68..8b28447 100644
--- a/config.c
+++ b/config.c
@@ -927,9 +927,6 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.pager"))
-		return git_config_string(&pager_program, var, value);
-
 	if (!strcmp(var, "core.editor"))
 		return git_config_string(&editor_program, var, value);
 
diff --git a/pager.c b/pager.c
index ae46da9..d747f50 100644
--- a/pager.c
+++ b/pager.c
@@ -35,6 +35,13 @@ static void wait_for_pager_signal(int signo)
 	raise(signo);
 }
 
+static int core_pager_config(const char *var, const char *value, void *data)
+{
+	if (!strcmp(var, "core.pager"))
+		return git_config_string(&pager_program, var, value);
+	return 0;
+}
+
 const char *git_pager(int stdout_is_tty)
 {
 	const char *pager;
@@ -45,7 +52,7 @@ const char *git_pager(int stdout_is_tty)
 	pager = getenv("GIT_PAGER");
 	if (!pager) {
 		if (!pager_program)
-			git_config(git_default_config, NULL);
+			git_config(core_pager_config, NULL);
 		pager = pager_program;
 	}
 	if (!pager)
-- 
2.10.0.230.g6f8d04b

[PATCH 09/16] pager: make pager_program a file-local static

[Jeff King]

This variable is only ever used by the routines in pager.c,
and other parts of the code should always use those routines
(like git_pager()) to make decisions about which pager to
use. Let's reduce its scope to prevent accidents.

Signed-off-by: Jeff King <peff@peff.net>
---
 cache.h       | 1 -
 environment.c | 1 -
 pager.c       | 1 +
 3 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/cache.h b/cache.h
index 6738050..4f23952 100644
--- a/cache.h
+++ b/cache.h
@@ -1786,7 +1786,6 @@ extern void write_file(const char *path, const char *fmt, ...);
 
 /* pager.c */
 extern void setup_pager(void);
-extern const char *pager_program;
 extern int pager_in_use(void);
 extern int pager_use_color;
 extern int term_columns(void);
diff --git a/environment.c b/environment.c
index ca72464..c266428 100644
--- a/environment.c
+++ b/environment.c
@@ -40,7 +40,6 @@ size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
 size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
 size_t delta_base_cache_limit = 96 * 1024 * 1024;
 unsigned long big_file_threshold = 512 * 1024 * 1024;
-const char *pager_program;
 int pager_use_color = 1;
 const char *editor_program;
 const char *askpass_program;
diff --git a/pager.c b/pager.c
index d747f50..8aa0a82 100644
--- a/pager.c
+++ b/pager.c
@@ -7,6 +7,7 @@
 #endif
 
 static struct child_process pager_process = CHILD_PROCESS_INIT;
+static const char *pager_program;
 
 static void wait_for_pager(int in_signal)
 {
-- 
2.10.0.230.g6f8d04b

[PATCH 10/16] pager: use callbacks instead of configset

[Jeff King]

While the cached configset interface is more pleasant to
use, it is not appropriate for "early" config like pager
setup, which must sometimes do tricky things like reading
from ".git/config" even when we have not set up the
repository.

As a preparatory step to handling these cases better, let's
switch back to using the callback interface, which gives us
more control.

Note that this is essentially a revert of 586f414 (pager.c:
replace `git_config()` with `git_config_get_value()`,
2014-08-07), but with some minor style fixups and
modernizations.

Signed-off-by: Jeff King <peff@peff.net>
---
 pager.c | 47 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/pager.c b/pager.c
index 8aa0a82..46cc411 100644
--- a/pager.c
+++ b/pager.c
@@ -183,23 +183,42 @@ int decimal_width(uintmax_t number)
 	return width;
 }
 
-/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
-int check_pager_config(const char *cmd)
+struct pager_command_config_data {
+	const char *cmd;
+	int want;
+	char *value;
+};
+
+static int pager_command_config(const char *var, const char *value, void *vdata)
 {
-	int want = -1;
-	struct strbuf key = STRBUF_INIT;
-	const char *value = NULL;
-	strbuf_addf(&key, "pager.%s", cmd);
-	if (git_config_key_is_valid(key.buf) &&
-	    !git_config_get_value(key.buf, &value)) {
-		int b = git_config_maybe_bool(key.buf, value);
+	struct pager_command_config_data *data = vdata;
+	const char *cmd;
+
+	if (skip_prefix(var, "pager.", &cmd) && !strcmp(cmd, data->cmd)) {
+		int b = git_config_maybe_bool(var, value);
 		if (b >= 0)
-			want = b;
+			data->want = b;
 		else {
-			want = 1;
-			pager_program = xstrdup(value);
+			data->want = 1;
+			data->value = xstrdup(value);
 		}
 	}
-	strbuf_release(&key);
-	return want;
+
+	return 0;
+}
+
+/* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
+int check_pager_config(const char *cmd)
+{
+	struct pager_command_config_data data;
+
+	data.cmd = cmd;
+	data.want = -1;
+	data.value = NULL;
+
+	git_config(pager_command_config, &data);
+
+	if (data.value)
+		pager_program = data.value;
+	return data.want;
 }
-- 
2.10.0.230.g6f8d04b

[PATCH 11/16] pager: handle early config

[Jeff King]

The pager code is often run early in the git.c startup,
before we have actually found the repository. When we ask
git_config() to look for values like core.pager, it doesn't
know where to find the repo-level config, and will blindly
examine ".git/config" if it exists. That's why t7006 shows
that many pager-related features happen to work from the
top-level of a repository, but not from a subdirectory.

This patch pulls that ".git/config" hack explicitly into the
pager code. There are two reasons for this:

  1. We'd like to clean up the git_config() behavior, as
     looking at ".git/config" when we do not have a
     configured repository is often the wrong thing to do.
     But we'd prefer not to break the pager config any worse
     than it already is.

  2. It's one very tiny step on the road to ultimately
     making the pager config work consistently. If we
     eventually get an equivalent of setup_git_directory()
     that _just_ finds the directory and doesn't chdir() or
     set up any global state, we could plug it in here
     (instead of blindly looking at ".git/config").

Signed-off-by: Jeff King <peff@peff.net>
---
 pager.c | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/pager.c b/pager.c
index 46cc411..ae79643 100644
--- a/pager.c
+++ b/pager.c
@@ -43,6 +43,37 @@ static int core_pager_config(const char *var, const char *value, void *data)
 	return 0;
 }
 
+static void read_early_config(config_fn_t cb, void *data)
+{
+	git_config_with_options(cb, data, NULL, 1);
+
+	/*
+	 * Note that this is a really dirty hack that does the wrong thing in
+	 * many cases. The crux of the problem is that we cannot run
+	 * setup_git_directory() early on in git's setup, so we have no idea if
+	 * we are in a repository or not, and therefore are not sure whether
+	 * and how to read repository-local config.
+	 *
+	 * So if we _aren't_ in a repository (or we are but we would reject its
+	 * core.repositoryformatversion), we'll read whatever is in .git/config
+	 * blindly. Similarly, if we _are_ in a repository, but not at the
+	 * root, we'll fail to find .git/config (because it's really
+	 * ../.git/config, etc). See t7006 for a complete set of failures.
+	 *
+	 * However, we have historically provided this hack because it does
+	 * work some of the time (namely when you are at the top-level of a
+	 * valid repository), and would rarely make things worse (i.e., you do
+	 * not generally have a .git/config file sitting around).
+	 */
+	if (!startup_info->have_repository) {
+		struct git_config_source repo_config;
+
+		memset(&repo_config, 0, sizeof(repo_config));
+		repo_config.file = ".git/config";
+		git_config_with_options(cb, data, &repo_config, 1);
+	}
+}
+
 const char *git_pager(int stdout_is_tty)
 {
 	const char *pager;
@@ -53,7 +84,7 @@ const char *git_pager(int stdout_is_tty)
 	pager = getenv("GIT_PAGER");
 	if (!pager) {
 		if (!pager_program)
-			git_config(core_pager_config, NULL);
+			read_early_config(core_pager_config, NULL);
 		pager = pager_program;
 	}
 	if (!pager)
@@ -216,7 +247,7 @@ int check_pager_config(const char *cmd)
 	data.want = -1;
 	data.value = NULL;
 
-	git_config(pager_command_config, &data);
+	read_early_config(pager_command_config, &data);
 
 	if (data.value)
 		pager_program = data.value;
-- 
2.10.0.230.g6f8d04b

[PATCH 12/16] t1302: use "git -C"

[Jeff King]

This is shorter, and saves a subshell.

Signed-off-by: Jeff King <peff@peff.net>
---
 t/t1302-repo-version.sh | 30 ++++++------------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/t/t1302-repo-version.sh b/t/t1302-repo-version.sh
index 9bcd349..f859809 100755
--- a/t/t1302-repo-version.sh
+++ b/t/t1302-repo-version.sh
@@ -25,10 +25,7 @@ test_expect_success 'setup' '
 test_expect_success 'gitdir selection on normal repos' '
 	echo 0 >expect &&
 	git config core.repositoryformatversion >actual &&
-	(
-		cd test &&
-		git config core.repositoryformatversion >../actual2
-	) &&
+	git -C test config core.repositoryformatversion >actual2 &&
 	test_cmp expect actual &&
 	test_cmp expect actual2
 '
@@ -36,35 +33,20 @@ test_expect_success 'gitdir selection on normal repos' '
 test_expect_success 'gitdir selection on unsupported repo' '
 	# Make sure it would stop at test2, not trash
 	echo 99 >expect &&
-	(
-		cd test2 &&
-		git config core.repositoryformatversion >../actual
-	) &&
+	git -C test2 config core.repositoryformatversion >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'gitdir not required mode' '
 	git apply --stat test.patch &&
-	(
-		cd test &&
-		git apply --stat ../test.patch
-	) &&
-	(
-		cd test2 &&
-		git apply --stat ../test.patch
-	)
+	git -C test apply --stat ../test.patch &&
+	git -C test2 apply --stat ../test.patch
 '
 
 test_expect_success 'gitdir required mode' '
 	git apply --check --index test.patch &&
-	(
-		cd test &&
-		git apply --check --index ../test.patch
-	) &&
-	(
-		cd test2 &&
-		test_must_fail git apply --check --index ../test.patch
-	)
+	git -C test apply --check --index ../test.patch &&
+	test_must_fail git -C test2 apply --check --index ../test.patch
 '
 
 check_allow () {
-- 
2.10.0.230.g6f8d04b

[PATCH 13/16] test-config: setup git directory

[Jeff King]

The t1308 test script uses our test-config helper to read
repository-level config, but never actually sets up the
repository. This works because git_config() blindly reads
".git/config" even if we have not configured a repository.

This means that test-config won't work from a subdirectory,
though since it's just a helper for the test scripts, that's
not a big deal.

More important is that the behavior of git_config() is going
to change, and we want to make sure that t1308 continues to
work. We can just use setup_git_directory(), and not the
gentle form; there's no point in being flexible, as it's
just a helper for the tests.

Signed-off-by: Jeff King <peff@peff.net>
---
 t/helper/test-config.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/t/helper/test-config.c b/t/helper/test-config.c
index 3c6d08c..83a4f2a 100644
--- a/t/helper/test-config.c
+++ b/t/helper/test-config.c
@@ -72,6 +72,9 @@ int cmd_main(int argc, const char **argv)
 	const char *v;
 	const struct string_list *strptr;
 	struct config_set cs;
+
+	setup_git_directory();
+
 	git_configset_init(&cs);
 
 	if (argc < 2) {
-- 
2.10.0.230.g6f8d04b

[PATCH 14/16] config: only read .git/config from configured repos

[Jeff King]

When git_config() runs, it looks in the system, user-wide,
and repo-level config files. It gets the latter by calling
git_pathdup(), which in turn calls get_git_dir(). If we
haven't set up the git repository yet, this may simply
return ".git", and we will look at ".git/config".  This
seems like it would be helpful (presumably we haven't set up
the repository yet, so it tries to find it), but it turns
out to be a bad idea for a few reasons:

  - it's not sufficient, and therefore hides bugs in a
    confusing way. Config will be respected if commands are
    run from the top-level of the working tree, but not from
    a subdirectory.

  - it's not always true that we haven't set up the
    repository _yet_; we may not want to do it at all. For
    instance, if you run "git init /some/path" from inside
    another repository, it should not load config from the
    existing repository.

  - there might be a path ".git/config", but it is not the
    actual repository we would find via setup_git_directory().
    This may happen, e.g., if you are storing a git
    repository inside another git repository, but have
    munged one of the files in such a way that the
    inner repository is not valid (e.g., by removing HEAD).

We have at least two bugs of the second type in git-init,
introduced by ae5f677 (lazily load core.sharedrepository,
2016-03-11). It causes init to use git_configset(), which
loads all of the config, including values from the current
repo (if any).  This shows up in two ways:

  1. If we happen to be in an existing repository directory,
     we'll read and respect core.sharedrepository from it,
     even though it should have no bearing on the new
     repository. A new test in t1301 covers this.

  2. Similarly, if we're in an existing repo that sets
     core.logallrefupdates, that will cause init to fail to
     set it in a newly created repository (because it thinks
     that the user's templates already did so). A new test
     in t0001 covers this.

We also need to adjust an existing test in t1302, which
gives another example of why this patch is an improvement.

That test creates an embedded repository with a bogus
core.repositoryformatversion of "99". It wants to make sure
that we actually stop at the bogus repo rather than
continuing upward to find the outer repo. So it checks that
"git config core.repositoryformatversion" returns 99. But
that only works because we blindly read ".git/config", even
though we _know_ we're in a repository whose vintage we do
not understand.

After this patch, we avoid reading config from the unknown
vintage repository at all, which is a safer choice.  But we
need to tweak the test, since core.repositoryformatversion
will not return 99; it will claim that it could not find the
variable at all.

Signed-off-by: Jeff King <peff@peff.net>
---
 cache.h                 | 6 ++++++
 config.c                | 2 +-
 environment.c           | 7 +++++++
 t/t0001-init.sh         | 9 +++++++++
 t/t1301-shared-repo.sh  | 9 +++++++++
 t/t1302-repo-version.sh | 4 +---
 6 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/cache.h b/cache.h
index 4f23952..e9592d3 100644
--- a/cache.h
+++ b/cache.h
@@ -453,6 +453,12 @@ static inline enum object_type object_type(unsigned int mode)
  */
 extern const char * const local_repo_env[];
 
+/*
+ * Returns true iff we have a configured git repository (either via
+ * setup_git_directory, or in the environment via $GIT_DIR).
+ */
+int have_git_dir(void);
+
 extern int is_bare_repository_cfg;
 extern int is_bare_repository(void);
 extern int is_inside_git_dir(void);
diff --git a/config.c b/config.c
index 8b28447..1e4b617 100644
--- a/config.c
+++ b/config.c
@@ -1286,7 +1286,7 @@ static int do_git_config_sequence(config_fn_t fn, void *data)
 	int ret = 0;
 	char *xdg_config = xdg_config_home("config");
 	char *user_config = expand_user_path("~/.gitconfig");
-	char *repo_config = git_pathdup("config");
+	char *repo_config = have_git_dir() ? git_pathdup("config") : NULL;
 
 	current_parsing_scope = CONFIG_SCOPE_SYSTEM;
 	if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK, 0))
diff --git a/environment.c b/environment.c
index c266428..c0cce6b 100644
--- a/environment.c
+++ b/environment.c
@@ -195,6 +195,13 @@ int is_bare_repository(void)
 	return is_bare_repository_cfg && !get_git_work_tree();
 }
 
+int have_git_dir(void)
+{
+	return startup_info->have_repository
+		|| git_dir
+		|| getenv(GIT_DIR_ENVIRONMENT);
+}
+
 const char *get_git_dir(void)
 {
 	if (!git_dir)
diff --git a/t/t0001-init.sh b/t/t0001-init.sh
index a6fdd5e..8ffbbea 100755
--- a/t/t0001-init.sh
+++ b/t/t0001-init.sh
@@ -384,4 +384,13 @@ test_expect_success MINGW 'bare git dir not hidden' '
 	! is_hidden newdir
 '
 
+test_expect_success 'remote init from does not use config from cwd' '
+	rm -rf newdir &&
+	test_config core.logallrefupdates true &&
+	git init newdir &&
+	echo true >expect &&
+	git -C newdir config --bool core.logallrefupdates >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t1301-shared-repo.sh b/t/t1301-shared-repo.sh
index ac10875..7c28642 100755
--- a/t/t1301-shared-repo.sh
+++ b/t/t1301-shared-repo.sh
@@ -172,4 +172,13 @@ test_expect_success POSIXPERM 'forced modes' '
 	}" actual)"
 '
 
+test_expect_success POSIXPERM 'remote init does not use config from cwd' '
+	git config core.sharedrepository 0666 &&
+	umask 0022 &&
+	git init --bare child.git &&
+	echo "-rw-r--r--" >expect &&
+	modebits child.git/config >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t1302-repo-version.sh b/t/t1302-repo-version.sh
index f859809..ce4cff1 100755
--- a/t/t1302-repo-version.sh
+++ b/t/t1302-repo-version.sh
@@ -32,9 +32,7 @@ test_expect_success 'gitdir selection on normal repos' '
 
 test_expect_success 'gitdir selection on unsupported repo' '
 	# Make sure it would stop at test2, not trash
-	echo 99 >expect &&
-	git -C test2 config core.repositoryformatversion >actual &&
-	test_cmp expect actual
+	test_expect_code 1 git -C test2 config core.repositoryformatversion >actual
 '
 
 test_expect_success 'gitdir not required mode' '
-- 
2.10.0.230.g6f8d04b

[PATCH 15/16] init: expand comments explaining config trickery

[Jeff King]

git-init may copy "config" from the templates directory and
then re-read it. There are some comments explaining what's
going on here, but they are not grouped very well with the
matching code. Let's rearrange and expand them.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/init-db.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/builtin/init-db.c b/builtin/init-db.c
index 3a45f0b..e935895 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -191,16 +191,19 @@ static int create_default_files(const char *template_path)
 	/* Just look for `init.templatedir` */
 	git_config(git_init_db_config, NULL);
 
-	/* First copy the templates -- we might have the default
+	/*
+	 * First copy the templates -- we might have the default
 	 * config file there, in which case we would want to read
 	 * from it after installing.
 	 */
 	copy_templates(template_path);
-
 	git_config(git_default_config, NULL);
-	is_bare_repository_cfg = init_is_bare_repository;
 
-	/* reading existing config may have overwrote it */
+	/*
+	 * We must make sure command-line options continue to override any
+	 * values we might have just re-read from the config.
+	 */
+	is_bare_repository_cfg = init_is_bare_repository;
 	if (init_shared_repository != -1)
 		set_shared_repository(init_shared_repository);
 
-- 
2.10.0.230.g6f8d04b

[PATCH 16/16] init: reset cached config when entering new repo

[Jeff King]

After we copy the templates into place, we re-read the
config in case we copied in a default config file. But since
git_config() is backed by a cache these days, it's possible
that the call will not actually touch the filesystem at all;
we need to tell it that something has changed behind the
scenes.

Note that we also need to reset the shared_repository
config. At first glance, it seems like this should probably
just be folded into git_config_clear(). But unfortunately
that is not quite right. The shared repository value may
come from config, _or_ it may have been set manually. So
only the caller who knows whether or not they set it is the
one who can clear it (and indeed, if you _do_ put it into
git_config_clear(), then many tests fail, as we have to
clear the config cache any time we set a new config
variable).

There are three tests here. The first two actually pass
already, though it's largely luck: they just don't happen to
actually read any config before we enter the new repo.

But the third one does fail without this patch; we look at
core.sharedrepository while creating the directory, but need
to make sure the value from the template config overrides
it.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/init-db.c      |  6 ++++++
 cache.h                |  7 +++++++
 environment.c          |  5 +++++
 t/t1301-shared-repo.sh | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 50 insertions(+)

diff --git a/builtin/init-db.c b/builtin/init-db.c
index e935895..cea4550 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -195,8 +195,14 @@ static int create_default_files(const char *template_path)
 	 * First copy the templates -- we might have the default
 	 * config file there, in which case we would want to read
 	 * from it after installing.
+	 *
+	 * Before reading that config, we also need to clear out any cached
+	 * values (since we've just potentially changed what's available on
+	 * disk).
 	 */
 	copy_templates(template_path);
+	git_config_clear();
+	reset_shared_repository();
 	git_config(git_default_config, NULL);
 
 	/*
diff --git a/cache.h b/cache.h
index e9592d3..4c8d85b 100644
--- a/cache.h
+++ b/cache.h
@@ -671,8 +671,15 @@ extern size_t delta_base_cache_limit;
 extern unsigned long big_file_threshold;
 extern unsigned long pack_size_limit_cfg;
 
+/*
+ * Accessors for the core.sharedrepository config which lazy-load the value
+ * from the config (if not already set). The "reset" function can be
+ * used to unset "set" or cached value, meaning that the value will be loaded
+ * fresh from the config file on the next call to get_shared_repository().
+ */
 void set_shared_repository(int value);
 int get_shared_repository(void);
+void reset_shared_repository(void);
 
 /*
  * Do replace refs need to be checked this run?  This variable is
diff --git a/environment.c b/environment.c
index c0cce6b..cd5aa57 100644
--- a/environment.c
+++ b/environment.c
@@ -351,3 +351,8 @@ int get_shared_repository(void)
 	}
 	return the_shared_repository;
 }
+
+void reset_shared_repository(void)
+{
+	need_shared_repository_from_config = 1;
+}
diff --git a/t/t1301-shared-repo.sh b/t/t1301-shared-repo.sh
index 7c28642..1312004 100755
--- a/t/t1301-shared-repo.sh
+++ b/t/t1301-shared-repo.sh
@@ -181,4 +181,36 @@ test_expect_success POSIXPERM 'remote init does not use config from cwd' '
 	test_cmp expect actual
 '
 
+test_expect_success POSIXPERM 're-init respects core.sharedrepository (local)' '
+	git config core.sharedrepository 0666 &&
+	umask 0022 &&
+	echo whatever >templates/foo &&
+	git init --template=templates &&
+	echo "-rw-rw-rw-" >expect &&
+	modebits .git/foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success POSIXPERM 're-init respects core.sharedrepository (remote)' '
+	rm -rf child.git &&
+	umask 0022 &&
+	git init --bare --shared=0666 child.git &&
+	test_path_is_missing child.git/foo &&
+	git init --bare --template=../templates child.git &&
+	echo "-rw-rw-rw-" >expect &&
+	modebits child.git/foo >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success POSIXPERM 'template can set core.sharedrepository' '
+	rm -rf child.git &&
+	umask 0022 &&
+	git config core.sharedrepository 0666 &&
+	cp .git/config templates/config &&
+	git init --bare --template=../templates child.git &&
+	echo "-rw-rw-rw-" >expect &&
+	modebits child.git/HEAD >actual &&
+	test_cmp expect actual
+'
+
 test_done
-- 
2.10.0.230.g6f8d04b

Re: [PATCH 01/16] t1007: factor out repeated setup

[Stefan Beller]

On Mon, Sep 12, 2016 at 8:23 PM, Jeff King <peff@peff.net> wrote:
> We have a series of 3 CRLF tests that do exactly the same
> (long) setup sequence. Let's pull it out into a common setup
> test, which is shorter, more efficient, and will make it
> easier to add new tests.
>
> Note that we don't have to worry about cleaning up any of
> the setup which was previously per-test; we call pop_repo
> after the CRLF tests, which cleans up everything.
>
> Signed-off-by: Jeff King <peff@peff.net>

This makes sense and looks good,
Thanks,

Reviewed-by: Stefan Beller <sbeller@google.com>

Re: [PATCH 06/16] diff: always try to set up the repository

[Stefan Beller]

On Mon, Sep 12, 2016 at 8:23 PM, Jeff King <peff@peff.net> wrote:

>   2. If you're in a subdirectory of a repository, then we
>      still try to read ".git/config", but it generally
>      doesn't exist. So "diff --no-index" there does not
>      respect repo config.

Nit:
So IIUC your cover letter even this /used/ to work but
broke only recently? So I feel like the message is a bit
misleading (i.e. you argue for a change in behavior instead of
calling it a bug fix for a regression. I think a bug fix for a regression
is harder to revert as compared to a "new" behavior)

I agree on the code, though.

Re: [PATCH 16/16] init: reset cached config when entering new repo

[Stefan Beller]

I have reviewed all patches though I am no expert on
the init routines. They all look good except for the one
nit I noted for the commit message in patch 6.
With that, the whole series is:
Reviewed-by: Stefan Beller <sbeller@google.com>

Thanks!

Re: [PATCH 06/16] diff: always try to set up the repository

[Jeff King]

On Tue, Sep 13, 2016 at 03:00:17PM -0700, Stefan Beller wrote:

> On Mon, Sep 12, 2016 at 8:23 PM, Jeff King <peff@peff.net> wrote:
> 
> >   2. If you're in a subdirectory of a repository, then we
> >      still try to read ".git/config", but it generally
> >      doesn't exist. So "diff --no-index" there does not
> >      respect repo config.
> 
> Nit:
> So IIUC your cover letter even this /used/ to work but
> broke only recently? So I feel like the message is a bit
> misleading (i.e. you argue for a change in behavior instead of
> calling it a bug fix for a regression. I think a bug fix for a regression
> is harder to revert as compared to a "new" behavior)

No, this has always been broken. What broke recently is the tests
covered in patch 14 related to git-init.

IOW, we have always done this "blind read" of .git/config, ever since
the early days. It was always wrong, but was mostly overlooked because
it worked often enough and usually didn't cause other problems. But
because of the caching and lazy-reading done by git_config() these days
(and get_shared_repository() which builds on it), you can get quite
confusing and buggy effects if you lazy-read at the wrong time.

-Peff

Re: [PATCH 0/16] fix config-reading in non-repos

[Dennis Kaarsemaker]

On ma, 2016-09-12 at 23:22 -0400, Jeff King wrote:

> The motivation for this series is to fix the regression in v2.9 where
> core.logallrefupdates is sometimes not set properly in a newly
> initialized repository, as described in this thread:
> 
>   http://public-inbox.org/git/c46d36ef-3c2e-374f-0f2e-ffe31104e023@gmx.de/T/#u
> 
> The root of the problem is that we are overly eager to read and use
> config from ".git/config", even when we have not established that it is
> part of a repository. This is especially bad for git-init, which would
> not want to read anything until we've created the new repo.
> 
> So the two interesting parts of the fix are:
> 
>   1. We stop blindly reading ".git/config" when we don't know there's an
>      actual git directory. This is in patch 14, and is actually enough
>      to fix the v2.9 regression.
> 
>   2. We are more thorough about dropping any cached config values when
>      we move into the new repository in git-init (patch 16).
> 
>      I didn't dig into when this was broken, but it was probably when we
>      switched git_config() to use cached values in the v2.2.0
>      time-frame.
> 
> Doing (1) required fixing up some builtins that depended on the blind
> .git/config thing, as the tests demonstrated. But I think this is a sign
> that we are moving in the right direction, because each one of those
> programs could easily be demonstrated to be broken in scenarios only
> slightly more exotic than the test scripts (e.g., see patch 3 for one of
> the simplest cases).
> 
> So I think notwithstanding their use as prep for patch 14, patches 1-13
> fix useful bugs.
> 
> I won't be surprised if there are other fallouts that were not caught by
> the test suite (i.e., programs that expect to read config, don't do
> RUN_SETUP, but aren't covered well by tests). I poked around the list of
> builtins in git.c that do not use RUN_SETUP, and they seem to correctly
> end up in setup_git_directory_gently() before reading config. But it's
> possible I missed a case.
> 
> So this is definitely a bit larger than I'd hope for a regression-fix to
> maint. But anything that doesn't address this issue at the config layer
> is going to end up as a bit of a hack, and I'd rather not pile up hacks
> if we can avoid it.

Agreed with all of the above, this is much better than just fixing the
symptom on the mailinglist thread that started this.

> I've cc'd Dennis, who helped investigate solutions in the thread
> mentioned above, and Duy, because historically he has been the one most
> willing and able to battle the dragon of our setup code. :)
> 
>   [01/16]: t1007: factor out repeated setup
>   [02/16]: hash-object: always try to set up the git repository
>   [03/16]: patch-id: use RUN_SETUP_GENTLY
>   [04/16]: diff: skip implicit no-index check when given --no-index
>   [05/16]: diff: handle --no-index prefixes consistently
>   [06/16]: diff: always try to set up the repository
>   [07/16]: pager: remove obsolete comment
>   [08/16]: pager: stop loading git_default_config()
>   [09/16]: pager: make pager_program a file-local static
>   [10/16]: pager: use callbacks instead of configset
>   [11/16]: pager: handle early config
>   [12/16]: t1302: use "git -C"
>   [13/16]: test-config: setup git directory
>   [14/16]: config: only read .git/config from configured repos
>   [15/16]: init: expand comments explaining config trickery
>   [16/16]: init: reset cached config when entering new repo

Couldn't find anything to comment on, and I've tested that this does
indeed fix the symptoms we saw.

Reviewed-by: Dennis Kaarsemaker <dennis@kaarsemaker.net>

-- 
Dennis Kaarsemaker
http://www.kaarsemaker.net

Re: [PATCH 0/16] fix config-reading in non-repos

[Jeff King]

On Wed, Sep 14, 2016 at 12:55:41PM +0200, Dennis Kaarsemaker wrote:

> >   [14/16]: config: only read .git/config from configured repos
> >   [15/16]: init: expand comments explaining config trickery
> >   [16/16]: init: reset cached config when entering new repo
> 
> Couldn't find anything to comment on, and I've tested that this does
> indeed fix the symptoms we saw.
> 
> Reviewed-by: Dennis Kaarsemaker <dennis@kaarsemaker.net>

Thanks. Based on our conversations earlier, I tried to dig around for
other cases that might be broken, especially with the "reinit" cases.
The result is the tests in patch 16. But let me know if you can think of
anything else that might be broken.

-Peff