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

From
Jeff King <peff@peff.net>
Date
Sep 13, 2016, 03:23 UTC
Message-ID
<20160913032336.cur3rrzpgepulqi6@sigill.intra.peff.net>
In-Reply-To
<20160913032242.coyuhyhn6uklewuk@sigill.intra.peff.net>

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
Previous: Jeff KingNext: Stefan Beller
Message 5 of 23 in “fix config-reading in non-repos”
  1. 0/16 fix config-reading in non-reposJeff King, Sep 13, 2016
  2. 01/16 t1007: factor out repeated setupJeff King, Sep 13, 2016
  3. Stefan BellerSep 13, 2016
  4. 02/16 hash-object: always try to set up the git repositoryJeff King, Sep 13, 2016
  5. 06/16 diff: always try to set up the repositoryJeff King, Sep 13, 2016
  6. Stefan BellerSep 13, 2016
  7. Jeff KingSep 13, 2016
  8. 04/16 diff: skip implicit no-index check when given --no-indexJeff King, Sep 13, 2016
  9. 07/16 pager: remove obsolete commentJeff King, Sep 13, 2016
  10. 03/16 patch-id: use RUN_SETUP_GENTLYJeff King, Sep 13, 2016
  11. 05/16 diff: handle --no-index prefixes consistentlyJeff King, Sep 13, 2016
  12. 08/16 pager: stop loading git_default_config()Jeff King, Sep 13, 2016
  13. 09/16 pager: make pager_program a file-local staticJeff King, Sep 13, 2016
  14. 10/16 pager: use callbacks instead of configsetJeff King, Sep 13, 2016
  15. 11/16 pager: handle early configJeff King, Sep 13, 2016
  16. 12/16 t1302: use "git -C"Jeff King, Sep 13, 2016
  17. 13/16 test-config: setup git directoryJeff King, Sep 13, 2016
  18. 14/16 config: only read .git/config from configured reposJeff King, Sep 13, 2016
  19. 15/16 init: expand comments explaining config trickeryJeff King, Sep 13, 2016
  20. 16/16 init: reset cached config when entering new repoJeff King, Sep 13, 2016
  21. Stefan BellerSep 13, 2016
  22. Dennis KaarsemakerSep 14, 2016
  23. Jeff KingSep 14, 2016

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