Merge branch 'tb/config-fixed-value-with-valueless-true' into maint-2.46

"git config --value=foo --fixed-value section.key newvalue" barfed
when the existing value in the configuration file used the
valueless true syntax, which has been corrected.

* tb/config-fixed-value-with-valueless-true:
  config.c: avoid segfault with --fixed-value and valueless config

Author: gitster

config.c

@@ -2914,7 +2914,7 @@ static int matches(const char *key, const char *value,
 {
 	if (strcmp(key, store->key))
 		return 0; /* not ours */
-	if (store->fixed_value)
+	if (store->fixed_value && value)
 		return !strcmp(store->fixed_value, value);
 	if (!store->value_pattern)
 		return 1; /* always matches */

t/t1300-config.sh

@@ -2704,6 +2704,15 @@ test_expect_success '--get and --get-all with --fixed-value' '
 	test_must_fail git config --file=config --get-regexp --fixed-value fixed+ non-existent
 '
 
+test_expect_success '--fixed-value with value-less configuration' '
+	test_when_finished rm -f config &&
+	cat >config <<-\EOF &&
+	[section]
+		key
+	EOF
+	git config --file=config --fixed-value section.key value pattern
+'
+
 test_expect_success 'includeIf.hasconfig:remote.*.url' '
 	git init hasremoteurlTest &&
 	test_when_finished "rm -rf hasremoteurlTest" &&