From bd8c1a9b49933c766587c65de70a0b8ff518801f Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Tue, 17 Jul 2012 22:08:59 -0700 Subject: [PATCH 1/2] diff: correctly disable external_diff with --no-ext-diff Upon seeing a type-change filepair, "diff --no-ext-diff" does not show the usual "deletion followed by addition" split patch and does not run the external diff driver either. This is because the logic to disable external diff was placed at a wrong level in the callchain. run_diff_cmd() decides to show the split patch only when external diff driver is not configured or specified via GIT_EXTERNAL_DIFF environment, but this is done before checking if --no-ext-diff was given. To make things worse, run_diff_cmd() checks --no-ext-diff and disables the output for such a filepair completely, as the callchain below it (e.g. builtin_diff) does not want to handle typechange filepairs. Signed-off-by: Junio C Hamano --- diff.c | 8 +++++--- t/t4020-diff-external.sh | 19 +++++++++++++++++++ 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/diff.c b/diff.c index 5388ded214..f4b58709eb 100644 --- a/diff.c +++ b/diff.c @@ -2913,9 +2913,8 @@ static void run_diff_cmd(const char *pgm, int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score; int must_show_header = 0; - if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL)) - pgm = NULL; - else { + + if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) { struct userdiff_driver *drv = userdiff_find_by_path(attr_path); if (drv && drv->external) pgm = drv->external; @@ -2995,6 +2994,9 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o) if (o->prefix_length) strip_prefix(o->prefix_length, &name, &other); + if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL)) + pgm = NULL; + if (DIFF_PAIR_UNMERGED(p)) { run_diff_cmd(pgm, name, NULL, attr_path, NULL, NULL, NULL, o, p); diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh index 083f62d1d6..025df533ca 100755 --- a/t/t4020-diff-external.sh +++ b/t/t4020-diff-external.sh @@ -48,7 +48,26 @@ test_expect_success 'GIT_EXTERNAL_DIFF environment and --no-ext-diff' ' ' +test_expect_success SYMLINKS 'typechange diff' ' + rm -f file && + ln -s elif file && + GIT_EXTERNAL_DIFF=echo git diff | { + read path oldfile oldhex oldmode newfile newhex newmode && + test "z$path" = zfile && + test "z$oldmode" = z100644 && + test "z$newhex" = "z$_z40" && + test "z$newmode" = z120000 && + oh=$(git rev-parse --verify HEAD:file) && + test "z$oh" = "z$oldhex" + } && + GIT_EXTERNAL_DIFF=echo git diff --no-ext-diff >actual && + git diff >expect && + test_cmp expect actual +' + test_expect_success 'diff attribute' ' + git reset --hard && + echo third >file && git config diff.parrot.command echo && From c12f82ae631eb07d0ee6a61003754d103025a0b3 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Thu, 19 Jul 2012 07:49:38 -0400 Subject: [PATCH 2/2] diff: test precedence of external diff drivers There are three ways to specify an external diff command: GIT_EXTERNAL_DIFF in the environment, diff.external in the config, or a "diff" gitattribute. The current order of precedence is: 1. gitattribute 2. GIT_EXTERNAL_DIFF 3. diff.external Usually our rule is that environment variables should take precedence over on-disk config (i.e., option 2 should come before option 1). However, this situation is trickier than some, because option 1 is more specific to the individual file than option 2 (which affects all files), so it might be preferable. So the current behavior can be seen as implementing "do the specific thing if we can, but fall back to this general thing". This is probably not what we would do if we were writing git from scratch, but it has been this way for several years, and is not worth changing. So let's at least document that this is the way it's supposed to work with a test. While we're there, let's also make sure that diff.external (which was not previously tested at all) works by running it through the same tests as GIT_EXTERNAL_DIFF. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- t/t4020-diff-external.sh | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/t/t4020-diff-external.sh b/t/t4020-diff-external.sh index 025df533ca..8a309795c9 100755 --- a/t/t4020-diff-external.sh +++ b/t/t4020-diff-external.sh @@ -65,6 +65,33 @@ test_expect_success SYMLINKS 'typechange diff' ' test_cmp expect actual ' +test_expect_success 'diff.external' ' + git reset --hard && + echo third >file && + test_config diff.external echo && + git diff | { + read path oldfile oldhex oldmode newfile newhex newmode && + test "z$path" = zfile && + test "z$oldmode" = z100644 && + test "z$newhex" = "z$_z40" && + test "z$newmode" = z100644 && + oh=$(git rev-parse --verify HEAD:file) && + test "z$oh" = "z$oldhex" + } +' + +test_expect_success 'diff.external should apply only to diff' ' + test_config diff.external echo && + git log -p -1 HEAD | + grep "^diff --git a/file b/file" +' + +test_expect_success 'diff.external and --no-ext-diff' ' + test_config diff.external echo && + git diff --no-ext-diff | + grep "^diff --git a/file b/file" +' + test_expect_success 'diff attribute' ' git reset --hard && echo third >file && @@ -132,6 +159,19 @@ test_expect_success 'diff attribute and --no-ext-diff' ' ' +test_expect_success 'GIT_EXTERNAL_DIFF trumps diff.external' ' + >.gitattributes && + test_config diff.external "echo ext-global" && + GIT_EXTERNAL_DIFF="echo ext-env" git diff | grep ext-env +' + +test_expect_success 'attributes trump GIT_EXTERNAL_DIFF and diff.external' ' + test_config diff.foo.command "echo ext-attribute" && + test_config diff.external "echo ext-global" && + echo "file diff=foo" >.gitattributes && + GIT_EXTERNAL_DIFF="echo ext-env" git diff | grep ext-attribute +' + test_expect_success 'no diff with -diff' ' echo >.gitattributes "file -diff" && git diff | grep Binary