Yes, I was fixing the invalid (!pgm) condition, sorry for a non-precise description. Does it mean that my patch is accepted or is there something else I need to do? -- Jakub Vrana -----Original Message----- From: Jeff King [mailto:peff@xxxxxxxx] Sent: Monday, July 16, 2012 9:16 PM To: Jakub Vrana Cc: git@xxxxxxxxxxxxxxx; gitster@xxxxxxxxx Subject: Re: [PATCH] diff: respect --no-ext-diff with typechange On Mon, Jul 16, 2012 at 05:27:00PM -0700, Jakub Vrana wrote: > If external diff is specified through diff.external then it is used > even if `git diff --no-ext-diff` is used when there is a typechange. Eek. That has some minor security implications, as it means that it is dangerous to run even plumbing inspection command in somebody else's repository. However... > diff.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/diff.c b/diff.c > index 208096f..898d610 100644 > --- a/diff.c > +++ b/diff.c > @@ -3074,6 +3074,9 @@ static void run_diff(struct diff_filepair *p, > struct diff_options *o) > if (o->prefix_length) > strip_prefix(o->prefix_length, &name, &other); > > + if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL)) > + pgm = NULL; > + > if (DIFF_PAIR_UNMERGED(p)) { > run_diff_cmd(pgm, name, NULL, attr_path, > NULL, NULL, NULL, o, p); run_diff_cmd already checks the ALLOW_EXTERNAL bit and sets pgm to NULL there. So as far as I can tell, we are not actually running the external diff. However, there is still a problem. Later in run_diff we do: if (!pgm && DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) && (S_IFMT & one->mode) != (S_IFMT & two->mode)) { /* * a filepair that changes between file and symlink * needs to be split into deletion and creation. */ struct diff_filespec *null = alloc_filespec(two->path); run_diff_cmd(NULL, name, other, attr_path, one, null, &msg, o, p); free(null); strbuf_release(&msg); null = alloc_filespec(one->path); run_diff_cmd(NULL, name, other, attr_path, null, two, &msg, o, p); free(null); } else run_diff_cmd(pgm, name, other, attr_path, one, two, &msg, o, p); IOW, we split up a typechange if we are feeding it to the internal diff generator, because builtin_diff will not show diffs between different types. But the check for "!pgm" here is not right; we don't know yet whether we will be builtin or external, because we have not checked ALLOW_EXTERNAL yet. So I think your fix is the right thing, but the bug it is fixing is not "do not run external diff even when --no-ext-diff is specified". It is "do not accidentally feed typechange diffs to builtin_diff". You can see the difference in output with this script (and it works fine with your patch applied): git init -q repo && cd repo && echo content >file && git add file && git commit -q -m regular && rm file && ln -s dest file && git commit -q -a -m typechange && export GIT_PAGER=cat && export GIT_EXTERNAL_DIFF='echo doing external diff' && git show HEAD^ --format='=== %s, ext ===' --ext-diff && git show HEAD^ --format='=== %s, no-ext ===' --no-ext-diff && git show HEAD --format='=== %s, ext ===' --ext-diff && git show HEAD --format='=== %s, no-ext ===' --no-ext-diff -Peff -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html