Merge branch 'jk/log-decorate-opts-with-implicit-decorate'

When "git log" implicitly enabled the "decoration" processing
without being explicitly asked with "--decorate" option, it failed
to read and honor the settings given by the "--decorate-refs"
option.

* jk/log-decorate-opts-with-implicit-decorate:
  log: load decorations with --simplify-by-decoration
  log: handle --decorate-refs with userformat "%d"

builtin/log.c

@@ -245,10 +245,24 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 			rev->abbrev_commit = 0;
 	}
 
-	if (rev->commit_format == CMIT_FMT_USERFORMAT && !w.decorate)
-		decoration_style = 0;
+	if (rev->commit_format == CMIT_FMT_USERFORMAT) {
+		if (!w.decorate) {
+			/*
+			 * Disable decoration loading if the format will not
+			 * show them anyway.
+			 */
+			decoration_style = 0;
+		} else if (!decoration_style) {
+			/*
+			 * If we are going to show them, make sure we do load
+			 * them here, but taking care not to override a
+			 * specific style set by config or --decorate.
+			 */
+			decoration_style = DECORATE_SHORT_REFS;
+		}
+	}
 
-	if (decoration_style) {
+	if (decoration_style || rev->simplify_by_decoration) {
 		const struct string_list *config_exclude =
 			repo_config_get_value_multi(the_repository,
 						    "log.excludeDecoration");
@@ -260,7 +274,8 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 						   item->string);
 		}
 
-		rev->show_decorations = 1;
+		if (decoration_style)
+			rev->show_decorations = 1;
 
 		load_ref_decorations(&decoration_filter, decoration_style);
 	}

t/t4202-log.sh

@@ -952,6 +952,43 @@ test_expect_success 'decorate-refs-exclude and simplify-by-decoration' '
 	test_cmp expect.decorate actual
 '
 
+test_expect_success 'decorate-refs with implied decorate from format' '
+	cat >expect <<-\EOF &&
+	side-2 (tag: side-2)
+	side-1
+	EOF
+	git log --no-walk --format="%s%d" \
+		--decorate-refs="*side-2" side-1 side-2 \
+		>actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'implied decorate does not override option' '
+	cat >expect <<-\EOF &&
+	side-2 (tag: refs/tags/side-2, refs/heads/side)
+	side-1 (tag: refs/tags/side-1)
+	EOF
+	git log --no-walk --format="%s%d" \
+		--decorate=full side-1 side-2 \
+		>actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'decorate-refs and simplify-by-decoration without output' '
+	cat >expect <<-\EOF &&
+	side-2
+	initial
+	EOF
+	# Do not just use a --format without %d here; we want to
+	# make sure that we did not accidentally turn on displaying
+	# the decorations, too. And that requires one of the regular
+	# formats.
+	git log --decorate-refs="*side-2" --oneline \
+		--simplify-by-decoration >actual.raw &&
+	sed "s/^[0-9a-f]* //" <actual.raw >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'log.decorate config parsing' '
 	git log --oneline --decorate=full >expect.full &&
 	git log --oneline --decorate=short >expect.short &&