line-log: detect unsupported formats

If you use "log -L" with an output format like "--raw" or "--stat",
we'll silently ignore the format and just output the normal patch.
Let's detect and complain about this, which at least tells the user
what's going on.

The tests here aren't exhaustive over the set of all formats, but it
should at least let us know if somebody breaks the format-checking.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

revision.c

@@ -2683,6 +2683,10 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 	if (revs->first_parent_only && revs->bisect)
 		die(_("--first-parent is incompatible with --bisect"));
 
+	if (revs->line_level_traverse &&
+	    (revs->diffopt.output_format & ~(DIFF_FORMAT_PATCH | DIFF_FORMAT_NO_OUTPUT)))
+		die(_("-L does not yet support diff formats besides -p and -s"));
+
 	if (revs->expand_tabs_in_log < 0)
 		revs->expand_tabs_in_log = revs->expand_tabs_in_log_default;
 

t/t4211-line-log.sh

@@ -122,4 +122,14 @@ test_expect_success '-s shows only line-log commits' '
 	test_cmp expect actual
 '
 
+test_expect_success '-p shows the default patch output' '
+	git log -L1,24:b.c >expect &&
+	git log -L1,24:b.c -p >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--raw is forbidden' '
+	test_must_fail git log -L1,24:b.c --raw
+'
+
 test_done