From 5f107caed755dae950382fdafc76a33b31528caa Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 18 Aug 2023 16:59:28 -0700 Subject: [PATCH 1/5] diff: move the fallback "--exit-code" code down When "--exit-code" is asked and the code cannot just answer by comparing the object names on both sides but needs to inspect and compare the contents, there are two ways that the result is found out. Some output modes, like "--stat" and "--patch", inherently have to inspect the contents in order to show the differences in the way they do. The codepaths for these modes set the .found_changes bit as they compute what to show. However, other output modes do not need to inspect the contents to show the differences in the way they do. The most notable example is "--quiet", which does not need to compute any output to show. When they are asked to report "--exit-code", they run the codepaths for the "--patch" output with their output redirected to "/dev/null", only to set the .found_changes bit. Currently, this fallback invocation of "--patch" output is done after the "--stat" output format and its friends and before the "--patch" and internal callback logic. Move it to the end of the sequence to clarify the fallback status of this code block. Signed-off-by: Junio C Hamano --- diff.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) diff --git a/diff.c b/diff.c index d52db685f7..0ce678fc06 100644 --- a/diff.c +++ b/diff.c @@ -6551,6 +6551,21 @@ void diff_flush(struct diff_options *options) separator++; } + if (output_format & DIFF_FORMAT_PATCH) { + if (separator) { + emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0); + if (options->stat_sep) + /* attach patch instead of inline */ + emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP, + NULL, 0, 0); + } + + diff_flush_patch_all_file_pairs(options); + } + + if (output_format & DIFF_FORMAT_CALLBACK) + options->format_callback(q, options, options->format_callback_data); + if (output_format & DIFF_FORMAT_NO_OUTPUT && options->flags.exit_with_status && options->flags.diff_from_contents) { @@ -6572,21 +6587,6 @@ void diff_flush(struct diff_options *options) } } - if (output_format & DIFF_FORMAT_PATCH) { - if (separator) { - emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0); - if (options->stat_sep) - /* attach patch instead of inline */ - emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP, - NULL, 0, 0); - } - - diff_flush_patch_all_file_pairs(options); - } - - if (output_format & DIFF_FORMAT_CALLBACK) - options->format_callback(q, options, options->format_callback_data); - for (i = 0; i < q->nr; i++) diff_free_filepair(q->queue[i]); free_queue: From c9a3e724cf75b44e47cfca5ae37cd0d7864c2220 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 18 Aug 2023 16:59:29 -0700 Subject: [PATCH 2/5] diff: mode-only change should be noticed by "--patch -w --exit-code" The codepath to notice the content-level changes, taking certain no-op changes like "ignore whitespace" into account, forgot that a mode-only change is still a change. This resulted in $ git diff --patch --exit-code -w to exit with status 0 even when there is such a mode-only change, breaking both "--patch" and "--quiet" output formats. Teach the builtin_diff() codepath that creation and deletion as well as mode changes are all interesting changes. Note that the test specifically checks removal of an empty file, because if there is anything in the preimage (i.e. the removed file is not empty), the removal would still trigger textual patch output and the codepath for that does update .found_changes bit to report that it found an interesting change. We need to make sure that the .found_changes bit is set even without triggering textual patch output. Signed-off-by: Junio C Hamano --- diff.c | 3 +++ t/t4015-diff-whitespace.sh | 35 ++++++++++++++++++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/diff.c b/diff.c index 0ce678fc06..998d7ae20c 100644 --- a/diff.c +++ b/diff.c @@ -3497,18 +3497,21 @@ static void builtin_diff(const char *name_a, strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset); if (xfrm_msg) strbuf_addstr(&header, xfrm_msg); + o->found_changes = 1; must_show_header = 1; } else if (lbl[1][0] == '/') { strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset); if (xfrm_msg) strbuf_addstr(&header, xfrm_msg); + o->found_changes = 1; must_show_header = 1; } else { if (one->mode != two->mode) { strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset); strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset); + o->found_changes = 1; must_show_header = 1; } if (xfrm_msg) diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh index f3e20dd5bb..02731dccb9 100755 --- a/t/t4015-diff-whitespace.sh +++ b/t/t4015-diff-whitespace.sh @@ -1,7 +1,7 @@ #!/bin/sh # # Copyright (c) 2006 Johannes E. Schindelin -# +# Copyright (c) 2023 Google LLC test_description='Test special whitespace in diff engine. @@ -11,6 +11,39 @@ TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh . "$TEST_DIRECTORY"/lib-diff.sh +for opts in --patch --quiet -s +do + + test_expect_success "status with $opts (different)" ' + echo foo >x && + git add x && + echo bar >x && + test_expect_code 1 git diff -w $opts --exit-code x + ' + + test_expect_success POSIXPERM "status with $opts (mode differs)" ' + test_when_finished "git update-index --chmod=-x x" && + echo foo >x && + git add x && + git update-index --chmod=+x x && + test_expect_code 1 git diff -w $opts --exit-code x + ' + + test_expect_success "status with $opts (removing an empty file)" ' + : >x && + git add x && + rm x && + test_expect_code 1 git diff -w $opts --exit-code -- x + ' + + test_expect_success "status with $opts (different but equivalent)" ' + echo foo >x && + git add x && + echo " foo" >x && + git diff -w $opts --exit-code x + ' +done + test_expect_success "Ray Lehtiniemi's example" ' cat <<-\EOF >x && do { From e8efd863699c6927953ebff6cb317c5632b7324d Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 18 Aug 2023 16:59:30 -0700 Subject: [PATCH 3/5] diff: teach "--stat -w --exit-code" to notice differences When options like "-w" is used while "--exit-code" option is in effect, instead of the usual "do we have any filepair whose preimage and postimage have different ?" check, we need to compare the contents of the blobs, taking into account that certain changes are considered no-op. With the previous step, we taught "--patch" codepath to set the .found_changes bit correctly, even for a change that only affects the mode and not object. The "--stat" codepath, however, did not set the .found_changes bit at all. This lead to $ git diff --stat -w --exit-code for a change that does have an output to exit with status 0. Set the bit by inspecting the list of paths the diffstat output is given for (a mode-only change will still appear as a "0-line added 0-line deleted" change) to fix it. Signed-off-by: Junio C Hamano --- diff.c | 1 + t/t4015-diff-whitespace.sh | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/diff.c b/diff.c index 998d7ae20c..da965ff688 100644 --- a/diff.c +++ b/diff.c @@ -6901,6 +6901,7 @@ void compute_diffstat(struct diff_options *options, if (check_pair_status(p)) diff_flush_stat(p, options, diffstat); } + options->found_changes = !!diffstat->nr; } void diff_addremove(struct diff_options *options, diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh index 02731dccb9..230a89b951 100755 --- a/t/t4015-diff-whitespace.sh +++ b/t/t4015-diff-whitespace.sh @@ -11,7 +11,7 @@ TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh . "$TEST_DIRECTORY"/lib-diff.sh -for opts in --patch --quiet -s +for opts in --patch --quiet -s --stat --shortstat --dirstat=lines do test_expect_success "status with $opts (different)" ' From 5626558e639cb34a8e32f52260fa7d7393b1982c Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 18 Aug 2023 16:59:31 -0700 Subject: [PATCH 4/5] t4040: remove test that succeeded for a wrong reason "diff-tree -b --exit-code" without "--patch" exits with 0 status, not because it finds that the two input files are equivalent while ignoring whitespaces, but because the implied "--raw" mode always exits with 0 when whitespace tweaking options like "-b" and "-w" are given, which is a long-standing bug. We are about to fix it so that "--raw" and friends report the differences with the exit status (even though they ignore the whitespace tweaking options when producing their output), which will make this test, which succeeded for a wrong reason, start failing. Remove it. Signed-off-by: Junio C Hamano --- t/t4040-whitespace-status.sh | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/t/t4040-whitespace-status.sh b/t/t4040-whitespace-status.sh index e70e020ae9..eec3d73dc2 100755 --- a/t/t4040-whitespace-status.sh +++ b/t/t4040-whitespace-status.sh @@ -28,8 +28,7 @@ test_expect_success 'diff-tree --exit-code' ' test_expect_success 'diff-tree -b --exit-code' ' git diff -b --exit-code HEAD^ HEAD && - git diff-tree -b -p --exit-code HEAD^ HEAD && - git diff-tree -b --exit-code HEAD^ HEAD + git diff-tree -b -p --exit-code HEAD^ HEAD ' test_expect_success 'diff-index --cached --exit-code' ' From a64f8b25953b9cf0f6d81ed24e87448ae513b094 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 18 Aug 2023 16:59:32 -0700 Subject: [PATCH 5/5] diff: the -w option breaks --exit-code for --raw and other output modes The output from "--raw", "--name-status", and "--name-only" modes in "git diff" does depend on and does not reflect how certain different contents are considered equal, unlike "--patch" and "--stat" output modes do, when used with options like "-w" (another way of thinking about it is that it is not like we recompute the hash of the blob after removing all whitespaces to show "git diff --raw -w" output). But the fact that "--raw" and friends ignore "-w" is not a good excuse for "diff --raw -w --exit-code" to also ignore the request to report the differences with its exit status. When run without "-w", "git diff --exit-code --raw" does report with its exit status the differences as requested, and we should do the same when run with "-w", too. Signed-off-by: Junio C Hamano --- diff.c | 6 ++++++ t/t4015-diff-whitespace.sh | 8 ++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/diff.c b/diff.c index da965ff688..78f4e7518f 100644 --- a/diff.c +++ b/diff.c @@ -4744,6 +4744,10 @@ void diff_setup_done(struct diff_options *options) else options->prefix_length = 0; + /* + * --name-only, --name-status, --checkdiff, and -s + * turn other output format off. + */ if (options->output_format & (DIFF_FORMAT_NAME | DIFF_FORMAT_NAME_STATUS | DIFF_FORMAT_CHECKDIFF | @@ -6072,6 +6076,8 @@ static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt) fprintf(opt->file, "%s", diff_line_prefix(opt)); write_name_quoted(name_a, opt->file, opt->line_termination); } + + opt->found_changes = 1; } static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs) diff --git a/t/t4015-diff-whitespace.sh b/t/t4015-diff-whitespace.sh index 230a89b951..7fcffa4b11 100755 --- a/t/t4015-diff-whitespace.sh +++ b/t/t4015-diff-whitespace.sh @@ -11,8 +11,12 @@ TEST_PASSES_SANITIZE_LEAK=true . ./test-lib.sh . "$TEST_DIRECTORY"/lib-diff.sh -for opts in --patch --quiet -s --stat --shortstat --dirstat=lines +for opt_res in --patch --quiet -s --stat --shortstat --dirstat=lines \ + --raw! --name-only! --name-status! do + opts=${opt_res%!} expect_failure= + test "$opts" = "$opt_res" || + expect_failure="test_expect_code 1" test_expect_success "status with $opts (different)" ' echo foo >x && @@ -40,7 +44,7 @@ do echo foo >x && git add x && echo " foo" >x && - git diff -w $opts --exit-code x + $expect_failure git diff -w $opts --exit-code x ' done