[PATCH libinput 5/8] Add a atoi_safe helper for basic string conversions

[Peter Hutterer]

Does what you expect, and returns false on errors.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/libinput-util.h | 23 +++++++++++++++++++++++
 test/misc.c         | 43 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/src/libinput-util.h b/src/libinput-util.h
index 53fe85f..04a454f 100644
--- a/src/libinput-util.h
+++ b/src/libinput-util.h
@@ -26,6 +26,7 @@
 #define LIBINPUT_UTIL_H
 
 #include <unistd.h>
+#include <limits.h>
 #include <math.h>
 #include <stdarg.h>
 #include <stdbool.h>
@@ -352,4 +353,26 @@ us2ms(uint64_t us)
 	return (uint32_t)(us / 1000);
 }
 
+static inline bool
+atoi_safe(const char *str, int *val)
+{
+	char *endptr;
+	long v;
+
+	if (!str)
+		return false;
+
+	v = strtol(str, &endptr, 0);
+
+	if (str == endptr || *endptr != '\0')
+		return false;
+
+	if (v > INT_MAX || v < INT_MIN)
+		return false;
+
+	*val = v;
+
+	return true;
+}
+
 #endif /* LIBINPUT_UTIL_H */
diff --git a/test/misc.c b/test/misc.c
index d880496..07cc21e 100644
--- a/test/misc.c
+++ b/test/misc.c
@@ -772,6 +772,46 @@ START_TEST(dimension_prop_parser)
 }
 END_TEST
 
+START_TEST(atoi_safe_test)
+{
+	struct test_case {
+		const char *str;
+		bool success;
+		int value;
+	} tests[] = {
+		{ "0", true, 0 },
+		{ "-1", true, -1 },
+		{ "1", true, 1 },
+		{ "0xffff", true, 0xffff },
+		{ "077", true, 077 },
+		{ "abc", false, 0 },
+		{ "-1a", false, 0 },
+		{ "b-1", false, 0 },
+		{ "0xffffffffffffffff", false, 0 },
+		{ "0xffffffff", false, 0 },
+		{ NULL, false, 0 },
+	};
+	struct test_case *t = tests;
+	int val;
+	bool success;
+
+	while (t->str) {
+		val = 0x54;
+
+		success = atoi_safe(t->str, &val);
+		ck_assert_int_eq(success, t->success);
+		if (success)
+			ck_assert_int_eq(val, t->value);
+		else
+			ck_assert_int_eq(val, 0x54);
+		t++;
+	}
+
+	success = atoi_safe(NULL, &val);
+	ck_assert_int_eq(success, false);
+}
+END_TEST
+
 START_TEST(time_conversion)
 {
 	ck_assert_int_eq(us(10), 10);
@@ -793,7 +833,6 @@ litest_setup_tests(void)
 	litest_add_for_device("events:conversion", event_conversion_touch, LITEST_WACOM_TOUCH);
 	litest_add_for_device("events:conversion", event_conversion_gesture, LITEST_BCM5974);
 	litest_add_for_device("events:conversion", event_conversion_tablet, LITEST_WACOM_CINTIQ);
-	litest_add_no_device("bitfield_helpers", bitfield_helpers);
 
 	litest_add_no_device("context:refcount", context_ref_counting);
 	litest_add_no_device("config:status string", config_status_string);
@@ -805,4 +844,6 @@ litest_setup_tests(void)
 	litest_add_no_device("misc:parser", trackpoint_accel_parser);
 	litest_add_no_device("misc:parser", dimension_prop_parser);
 	litest_add_no_device("misc:time", time_conversion);
+	litest_add_no_device("misc:helpers", bitfield_helpers);
+	litest_add_no_device("misc:helpers", atoi_safe_test);
 }
-- 
2.5.0