From: Junio C Hamano <gitster@pobox.com>
To: git@vger.kernel.org
Cc: Sergey Organov <sorganov@gmail.com>
Subject: [PATCH] diff: fix behaviour of the "-s" option
Date: Thu, 04 May 2023 16:10:02 -0700 [thread overview]
Message-ID: <xmqqfs8bith1.fsf_-_@gitster.g> (raw)
In-Reply-To: <xmqqjzxnixqr.fsf_-_@gitster.g> (Junio C. Hamano's message of "Thu, 04 May 2023 14:37:48 -0700")
Junio C Hamano <gitster@pobox.com> writes:
> I haven't run any tests (not just your new one, but existing ones)
> but ...
And of course, not writing tests fails to even realize that the bug
has two components, "-s" failing to clear the bits previously set,
and other options not clearing the bit set by "-s".
This version may still be rough, but at least the full test suite
has been run with it, so I have a bit more confidence than the
earlier one (which may not mean much).
------- >8 ------------- >8 ------------- >8 -------------
Sergey Organov noticed and reported "--patch --no-patch --raw"
behaves differently from "--raw". It turns out there are a few
interesting bugs in the implementation and documentation.
* First, the documentation for "--no-patch" was unclear that it
could be read to mean "--no-patch" countermands an earlier
"--patch" but not other things. The intention of "--no-patch"
ever since it was introduced at d09cd15d (diff: allow --no-patch
as synonym for -s, 2013-07-16) was to serve as a synonym for
"-s", so "--raw --patch --no-patch" should have produced no
output, but it can be (mis)read to allow showing only "--raw"
output.
* Then the interaction between "-s" and other format options were
poorly implemented. Modern versions of Git uses one bit each to
represent formatting options like "--patch", "--stat" in a single
output_format word, but for historical reasons, "-s" also is
represented as another bit in the same word. This allows two
interesting bugs to happen, and we have both.
(1) After setting a format bit, then setting NO_OUTPUT with "-s",
the code to process another "--<format>" option drops the
NO_OUTPUT bit to allow output to be shown again. However,
the code to handle "-s" only set NO_OUTPUT without unsetting
format bits set earlier, so the earlier format bit got
revealed upon seeing the second "--<format>" option. THis is
the problem Sergey observed.
(2) After setting NO_OUTPUT with "-s", code to process
"--<format>" option can forget to unset NO_OUTPUT, leaving
the command still silent.
It is tempting to change the meaning of "--no-patch" to mean
"disable only the patch format output" and reimplement "-s" as "not
showing anything", but it would be an end-user visible change in
behaviour. Let's fix the interactions of these bits to first make
"-s" work as intended.
The fix is conceptually very simple.
* Whenever we set DIFF_FORMAT_FOO becasuse we saw the "--foo"
option (e.g. DIFF_FORMAT_RAW is set when the "--raw" option is
given), we make sure we drop DIFF_FORMAT_NO_OUTPUT. We forgot to
do so in some of the options and caused (2) above.
* When processing "-s" option, we should not just set
DIFF_FORMAT_NO_OUTPUT bit, but clear other DIFF_FORMAT_* bits.
We didn't do so and retained format bits set by options
previously seen, causing (1) above.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Documentation/diff-options.txt | 7 +++++--
diff.c | 24 +++++++++++++-----------
t/t4000-diff-format.sh | 32 +++++++++++++++++++++++++++++++-
3 files changed, 49 insertions(+), 14 deletions(-)
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 3674ac48e9..7d5bb65a49 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -29,8 +29,11 @@ endif::git-diff[]
-s::
--no-patch::
- Suppress diff output. Useful for commands like `git show` that
- show the patch by default, or to cancel the effect of `--patch`.
+ Suppress all output from the diff machinery. Useful for
+ commands like `git show` that show the patch by default to
+ squelch their output, or to cancel the effect of options like
+ `--patch`, `--stat` earlier on the command line in an alias.
+
endif::git-format-patch[]
ifdef::git-log[]
diff --git a/diff.c b/diff.c
index 648f6717a5..5a2f096683 100644
--- a/diff.c
+++ b/diff.c
@@ -4868,6 +4868,7 @@ static int diff_opt_stat(const struct option *opt, const char *value, int unset)
} else
BUG("%s should not get here", opt->long_name);
+ options->output_format &= ~DIFF_FORMAT_NO_OUTPUT;
options->output_format |= DIFF_FORMAT_DIFFSTAT;
options->stat_name_width = name_width;
options->stat_graph_width = graph_width;
@@ -4887,6 +4888,7 @@ static int parse_dirstat_opt(struct diff_options *options, const char *params)
* The caller knows a dirstat-related option is given from the command
* line; allow it to say "return this_function();"
*/
+ options->output_format &= ~DIFF_FORMAT_NO_OUTPUT;
options->output_format |= DIFF_FORMAT_DIRSTAT;
return 1;
}
@@ -5086,6 +5088,7 @@ static int diff_opt_compact_summary(const struct option *opt,
options->flags.stat_with_summary = 0;
} else {
options->flags.stat_with_summary = 1;
+ options->output_format &= ~DIFF_FORMAT_NO_OUTPUT;
options->output_format |= DIFF_FORMAT_DIFFSTAT;
}
return 0;
@@ -5404,9 +5407,8 @@ static void prep_parse_options(struct diff_options *options)
OPT_BITOP('p', "patch", &options->output_format,
N_("generate patch"),
DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
- OPT_BIT_F('s', "no-patch", &options->output_format,
- N_("suppress diff output"),
- DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
+ OPT_SET_INT('s', "no-patch", &options->output_format,
+ N_("suppress diff output"), DIFF_FORMAT_NO_OUTPUT),
OPT_BITOP('u', NULL, &options->output_format,
N_("generate patch"),
DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
@@ -5415,9 +5417,9 @@ static void prep_parse_options(struct diff_options *options)
PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_unified),
OPT_BOOL('W', "function-context", &options->flags.funccontext,
N_("generate diffs with <n> lines context")),
- OPT_BIT_F(0, "raw", &options->output_format,
+ OPT_BITOP(0, "raw", &options->output_format,
N_("generate the diff in raw format"),
- DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
+ DIFF_FORMAT_RAW, DIFF_FORMAT_NO_OUTPUT),
OPT_BITOP(0, "patch-with-raw", &options->output_format,
N_("synonym for '-p --raw'"),
DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
@@ -5426,12 +5428,12 @@ static void prep_parse_options(struct diff_options *options)
N_("synonym for '-p --stat'"),
DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
DIFF_FORMAT_NO_OUTPUT),
- OPT_BIT_F(0, "numstat", &options->output_format,
+ OPT_BITOP(0, "numstat", &options->output_format,
N_("machine friendly --stat"),
- DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
- OPT_BIT_F(0, "shortstat", &options->output_format,
+ DIFF_FORMAT_NUMSTAT, DIFF_FORMAT_NO_OUTPUT),
+ OPT_BITOP(0, "shortstat", &options->output_format,
N_("output only the last line of --stat"),
- DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
+ DIFF_FORMAT_SHORTSTAT, DIFF_FORMAT_NO_OUTPUT),
OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
N_("output the distribution of relative amount of changes for each sub-directory"),
PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
@@ -5447,9 +5449,9 @@ static void prep_parse_options(struct diff_options *options)
OPT_BIT_F(0, "check", &options->output_format,
N_("warn if changes introduce conflict markers or whitespace errors"),
DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
- OPT_BIT_F(0, "summary", &options->output_format,
+ OPT_BITOP(0, "summary", &options->output_format,
N_("condensed summary such as creations, renames and mode changes"),
- DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
+ DIFF_FORMAT_SUMMARY, DIFF_FORMAT_NO_OUTPUT),
OPT_BIT_F(0, "name-only", &options->output_format,
N_("show only names of changed files"),
DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
diff --git a/t/t4000-diff-format.sh b/t/t4000-diff-format.sh
index bfcaae390f..762b9d4c60 100755
--- a/t/t4000-diff-format.sh
+++ b/t/t4000-diff-format.sh
@@ -5,6 +5,9 @@
test_description='Test built-in diff output engine.
+We happen to know that all diff plumbing and diff Porcelain share the
+same command line parser, so testing one should be sufficient; pick
+diff-files as a representative.
'
TEST_PASSES_SANITIZE_LEAK=true
@@ -16,9 +19,11 @@ Line 2
line 3'
cat path0 >path1
chmod +x path1
+mkdir path2
+>path2/path3
test_expect_success 'update-index --add two files with and without +x.' '
- git update-index --add path0 path1
+ git update-index --add path0 path1 path2/path3
'
mv path0 path0-
@@ -91,4 +96,29 @@ test_expect_success 'git diff-files --patch --no-patch does not show the patch'
test_must_be_empty err
'
+
+# Smudge path2/path3 so that dirstat has something to show
+date >path2/path3
+
+for format in stat raw numstat shortstat dirstat
+do
+ test_expect_success "--no-patch in 'git diff-files --no-patch --$format' is a no-op" '
+ git diff-files --no-patch "--$format" >actual &&
+ git diff-files "--$format" >expect &&
+ test_cmp expect actual
+ '
+
+ test_expect_success "--no-patch clears all previous ones" '
+ git diff-files --$format -s -p >actual &&
+ git diff-files -p >expect &&
+ test_cmp expect actual
+ '
+
+ test_expect_success "--no-patch in 'git diff --no-patch --$format' is a no-op" '
+ git diff --no-patch "--$format" >actual &&
+ git diff "--$format" >expect &&
+ test_cmp expect actual
+ '
+done
+
test_done
--
2.40.1-476-g69c786637d
next prev parent reply other threads:[~2023-05-04 23:10 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-03 13:41 [PATCH] t4013: add expected failure for "log --patch --no-patch" Sergey Organov
2023-05-03 16:57 ` Junio C Hamano
2023-05-03 17:31 ` Sergey Organov
2023-05-03 18:07 ` Junio C Hamano
2023-05-03 18:32 ` Felipe Contreras
2023-05-03 19:49 ` Sergey Organov
2023-05-04 15:50 ` Junio C Hamano
2023-05-04 18:24 ` Sergey Organov
2023-05-04 20:53 ` Junio C Hamano
2023-05-04 21:37 ` Re* " Junio C Hamano
2023-05-04 23:10 ` Junio C Hamano [this message]
2023-05-05 5:28 ` [PATCH] diff: fix behaviour of the "-s" option Junio C Hamano
2023-05-05 16:51 ` Junio C Hamano
2023-05-09 1:16 ` Felipe Contreras
2023-05-05 8:32 ` Sergey Organov
2023-05-05 16:31 ` Junio C Hamano
2023-05-05 17:07 ` Sergey Organov
2023-05-05 16:59 ` [PATCH v2] diff: fix interaction between the "-s" option and other options Junio C Hamano
2023-05-05 17:41 ` Eric Sunshine
2023-05-05 19:01 ` Junio C Hamano
2023-05-05 21:19 ` [PATCH 0/2] dirstat: leakfix Junio C Hamano
2023-05-05 21:19 ` [PATCH 1/2] diff: refactor common tail part of dirstat computation Junio C Hamano
2023-05-05 21:19 ` [PATCH 2/2] diff: plug leaks in dirstat Junio C Hamano
2023-05-09 0:38 ` [PATCH v2] diff: fix interaction between the "-s" option and other options Felipe Contreras
2023-05-09 1:22 ` Junio C Hamano
2023-05-09 3:50 ` Felipe Contreras
2023-05-10 4:26 ` Junio C Hamano
2023-05-10 23:16 ` Felipe Contreras
2023-05-10 23:41 ` Felipe Contreras
2023-05-11 1:25 ` Jeff King
2023-05-13 3:07 ` Felipe Contreras
2023-05-11 1:50 ` Junio C Hamano
2023-05-13 5:32 ` Felipe Contreras
2023-05-09 1:34 ` [PATCH] t4013: add expected failure for "log --patch --no-patch" Felipe Contreras
2023-05-10 13:54 ` Sergey Organov
2023-05-10 21:54 ` Felipe Contreras
2023-05-09 1:03 ` Felipe Contreras
2023-05-04 18:07 ` Junio C Hamano
2023-05-04 18:26 ` Sergey Organov
2023-05-09 1:07 ` Felipe Contreras
2023-05-10 13:40 ` Sergey Organov
2023-05-10 21:39 ` Felipe Contreras
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=xmqqfs8bith1.fsf_-_@gitster.g \
--to=gitster@pobox.com \
--cc=git@vger.kernel.org \
--cc=sorganov@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).