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 <m...@mcrowe.com>
Helped-by: Torsten Bögershausen <tbo...@web.de>
Signed-off-by: Junio C Hamano <gits...@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
