From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Thu, 11 Mar 2021 23:19:38 +0000 (+0200)
Subject: lib: Optimize p_strndup()
X-Git-Tag: 2.3.17~101
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=de0871dedb4a06882e8a53ae80bb656d8db6752d;p=thirdparty%2Fdovecot%2Fcore.git

lib: Optimize p_strndup()
---

diff --git a/src/lib/strfuncs.c b/src/lib/strfuncs.c
index 7b5e54499a..68b67a2fb4 100644
--- a/src/lib/strfuncs.c
+++ b/src/lib/strfuncs.c
@@ -87,19 +87,21 @@ char *p_strdup_until(pool_t pool, const void *start, const void *end)
 
 char *p_strndup(pool_t pool, const void *str, size_t max_chars)
 {
+	const char *p;
 	char *mem;
 	size_t len;
 
 	i_assert(str != NULL);
 	i_assert(max_chars != SIZE_MAX);
 
-	len = 0;
-	while (len < max_chars && ((const char *) str)[len] != '\0')
-		len++;
+	p = memchr(str, '\0', max_chars);
+	if (p == NULL)
+		len = max_chars;
+	else
+		len = p - (const char *)str;
 
 	mem = p_malloc(pool, len+1);
 	memcpy(mem, str, len);
-	mem[len] = '\0';
 	return mem;
 }
 
diff --git a/src/lib/test-lib.inc b/src/lib/test-lib.inc
index 0591f86dc3..549c7bd4e1 100644
--- a/src/lib/test-lib.inc
+++ b/src/lib/test-lib.inc
@@ -95,6 +95,7 @@ TEST(test_stats_dist)
 TEST(test_str)
 TEST(test_strescape)
 TEST(test_strfuncs)
+FATAL(fatal_strfuncs)
 TEST(test_strnum)
 TEST(test_str_find)
 TEST(test_str_sanitize)
diff --git a/src/lib/test-strfuncs.c b/src/lib/test-strfuncs.c
index 5db2711037..b3c84fee7c 100644
--- a/src/lib/test-strfuncs.c
+++ b/src/lib/test-strfuncs.c
@@ -16,6 +16,29 @@ static void test_p_strdup(void)
 	test_end();
 }
 
+static void test_p_strndup(void)
+{
+	struct {
+		const char *input;
+		const char *output;
+		size_t len;
+	} tests[] = {
+		{ "foo", "fo", 2 },
+		{ "foo", "foo", 3 },
+		{ "foo", "foo", 4 },
+		{ "foo", "foo", SIZE_MAX-1 },
+	};
+	test_begin("p_strndup()");
+
+	for (unsigned int i = 0; i < N_ELEMENTS(tests); i++) {
+		char *str = p_strndup(default_pool, tests[i].input,
+				      tests[i].len);
+		test_assert_strcmp_idx(str, tests[i].output, i);
+		p_free(default_pool, str);
+	}
+	test_end();
+}
+
 static void test_p_strdup_empty(void)
 {
 	test_begin("p_strdup_empty()");
@@ -475,6 +498,7 @@ test_str_match(void)
 void test_strfuncs(void)
 {
 	test_p_strdup();
+	test_p_strndup();
 	test_p_strdup_empty();
 	test_p_strdup_until();
 	test_p_strarray_dup();
@@ -492,3 +516,20 @@ void test_strfuncs(void)
 	test_dec2str_buf();
 	test_str_match();
 }
+
+enum fatal_test_state fatal_strfuncs(unsigned int stage)
+{
+	switch (stage) {
+	case 0:
+		test_begin("fatal p_strndup()");
+		test_expect_fatal_string("(str != NULL)");
+		(void)p_strndup(default_pool, NULL, 100);
+		return FATAL_TEST_FAILURE;
+	case 1:
+		test_expect_fatal_string("(max_chars != SIZE_MAX)");
+		(void)p_strndup(default_pool, "foo", SIZE_MAX);
+		return FATAL_TEST_FAILURE;
+	}
+	test_end();
+	return FATAL_TEST_FINISHED;
+}