Thread (3 messages) flat view 3 messages, 2 authors, 2016-06-15

Re: [PATCH] diff: exit(1) if 'diff --quiet <repo file> <external file>' finds changes

From: Jeff King <hidden>
Date: 2016-06-15 22:54:07

On Fri, Jun 15, 2012 at 01:31:03PM -0400, Tim Henigan wrote:
When running 'git diff --quiet <file1> <file2>', if file1 or file2
is outside the repository, it will exit(0) even if the files differ.
It should exit(1) when they differ.
From your description, I would expect the fix to be in builtin/diff.c,
or in diff-no-index.c, since that is where the code paths diverge.
This was the least invasive fix that I found.  I considered adding
the following when the '--quiet' option is parsed instead:

+   DIFF_OPT_SET(options, EXIT_WITH_STATUS)
+   DIFF_OPT_SET(options, DIFF_FROM_CONTENTS)
We already set EXIT_WITH_STATUS when we see --quiet (we just do it a
little later, during diff_setup_done). We would not want to set
DIFF_FROM_CONTENTS all the time with --quiet. The point of that flag is
"we cannot know just from seeing the path sha1s whether they are
different or not, because we are doing content-level munging" (for
example, things like ignoring whitespace changes).

So we would not want to always set it whenever --quiet is given, because
it means we must do a lot of extra work comparing file content.
quoted hunk ↗ jump to hunk
diff --git a/diff.c b/diff.c
index 77edd50..b1d74fe 100644
--- a/diff.c
+++ b/diff.c
@@ -4432,9 +4432,10 @@ void diff_flush(struct diff_options *options)
 		separator++;
 	}
 
-	if (output_format & DIFF_FORMAT_NO_OUTPUT &&
+	if ((output_format & DIFF_FORMAT_NO_OUTPUT &&
 	    DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
-	    DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
+	    DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) ||
+		DIFF_OPT_TST(options, QUICK)) {
 		/*
 		 * run diff_flush_patch for the exit status. setting
 		 * options->file to /dev/null should be safe, becaue we
And this is equally bad, because it means that --quiet gets much slower
for _all_ cases, not just the no-index case.

I suspect what you actually want is to set DIFF_FROM_CONTENTS in the
no-index case, since we by definition do not have a pair of sha1s to
compare. But it may also be that diff.c could detect this case
automatically. I'd have to look closer.

-Peff
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help