[PATCH v2] diff: do not short-cut CHECK_SIZE_ONLY check in diff_populate_filespec()
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Mar 2, 2017, 18:51 UTC
- Message-ID
- <xmqqwpc7bjgi.fsf_-_@gitster.mtv.corp.google.com>
- In-Reply-To
- <20170302085313.r6dox4wa2kqnp7ao@sigill.intra.peff.net>
Callers of diff_populate_filespec() can choose to ask only for the size of the blob without grabbing the blob data, and the function, after running lstat() when the filespec points at a working tree file, returns by copying the value in size field of the stat structure into the size field of the filespec when this is the case.
However, this short-cut cannot be taken if the contents from the path needs to go through convert_to_git(), whose resulting real blob data may be different from what is in the working tree file.
As "git diff --quiet" compares the .size fields of filespec structures to skip content comparison, this bug manifests as a false "there are differences" for a file that needs eol conversion, for example.
Reported-by: Mike Crowe <mac@mcrowe.com> Helped-by: Torsten Bögershausen <tboegi@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com> ---
* With "test size_only to avoid more expensive would_convert call" fix applied. Also the new test is now in t4xxx that it belongs to.
diff.c | 19 ++++++++++++++++++- t/t4035-diff-quiet.sh | 9 +++++++++ 2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/diff.c b/diff.c index 059123c5dc..37e60ca601 100644 --- a/diff.c +++ b/diff.c @@ -2783,8 +2783,25 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags) s->should_free = 1; return 0; } - if (size_only) + + /* + * Even if the caller would be happy with getting + * only the size, we cannot return early at this + * point if the path requires us to run the content + * conversion. + */ + if (size_only && !would_convert_to_git(s->path)) return 0; + + /* + * Note: this check uses xsize_t(st.st_size) that may + * not be the true size of the blob after it goes + * through convert_to_git(). This may not strictly be + * correct, but the whole point of big_file_threshold + * and is_binary check being that we want to avoid + * opening the file and inspecting the contents, this + * is probably fine. + */ if ((flags & CHECK_BINARY) && s->size > big_file_threshold && s->is_binary == -1) { s->is_binary = 1; diff --git a/t/t4035-diff-quiet.sh b/t/t4035-diff-quiet.sh index 461f4bb583..2f1737fcef 100755 --- a/t/t4035-diff-quiet.sh +++ b/t/t4035-diff-quiet.sh @@ -152,4 +152,13 @@ test_expect_success 'git diff --quiet ignores stat-change only entries' ' test_expect_code 1 git diff --quiet ' +test_expect_success 'git diff --quiet on a path that need conversion' ' + echo "crlf.txt text=auto" >.gitattributes && + printf "Hello\r\nWorld\r\n" >crlf.txt && + git add .gitattributes crlf.txt && + + printf "Hello\r\nWorld\n" >crlf.txt && + git diff --quiet crlf.txt +' + test_done
-- 2.12.0-352-gb05ccab5eb