move "--follow needs one pathspec" rule to diff_setup_done

peff · gitster · commit dd63f169d938 · 2014-05-20T11:09:03.000-07:00
Because of the way "--follow" is implemented, we must have
exactly one pathspec. "git log" enforces this restriction,
but other users of the revision traversal code do not. For
example, "git format-patch --follow" will segfault during
try_to_follow_renames, as we have no pathspecs at all.

We can push this check down into diff_setup_done, which is
probably a better place anyway. It is the diff code that
introduces this restriction, so other parts of the code
should not need to care themselves.

Reported-by: "Michael S. Tsirkin" &lt;mst@redhat.com&gt;
Signed-off-by: Jeff King &lt;peff@peff.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/builtin/log.c b/builtin/log.c
@@ -158,13 +158,9 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 	if (rev->show_notes)
 		init_display_notes(&rev->notes_opt);
 
-	if (rev->diffopt.pickaxe || rev->diffopt.filter)
+	if (rev->diffopt.pickaxe || rev->diffopt.filter ||
+	    DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES))
 		rev->always_show_header = 0;
-	if (DIFF_OPT_TST(&rev->diffopt, FOLLOW_RENAMES)) {
-		rev->always_show_header = 0;
-		if (rev->diffopt.pathspec.nr != 1)
-			usage("git logs can only follow renames on one pathname at a time");
-	}
 
 	if (source)
 		rev->show_source = 1;
diff --git a/diff.c b/diff.c
@@ -3317,6 +3317,9 @@ void diff_setup_done(struct diff_options *options)
 		options->output_format = DIFF_FORMAT_NO_OUTPUT;
 		DIFF_OPT_SET(options, EXIT_WITH_STATUS);
 	}
+
+	if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
+		die(_("--follow requires exactly one pathspec"));
 }
 
 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)

Original file line number	Diff line number	Diff line change
`@@ -3317,6 +3317,9 @@ void diff_setup_done(struct diff_options *options)`
`3317`	`3317`	`options->output_format = DIFF_FORMAT_NO_OUTPUT;`
`3318`	`3318`	`DIFF_OPT_SET(options, EXIT_WITH_STATUS);`
`3319`	`3319`	`}`
	`3320`	`+`
	`3321`	`+ if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)`
	`3322`	`+ die(_("--follow requires exactly one pathspec"));`
`3320`	`3323`	`}`
`3321`	`3324`
`3322`	`3325`	`static int opt_arg(const char arg, int arg_short, const char arg_long, int *val)`