fmt/pl: rewrite negative handling (avoid undefined behavior) (#314)

baresip · Apr 11, 2022 · fe5ee51 · fe5ee51
1 parent 33763b0
commit fe5ee51
Showing 1 changed file with 12 additions and 6 deletions.
diff --git a/src/fmt/pl.c b/src/fmt/pl.c
@@ -63,7 +63,7 @@ void pl_set_mbuf(struct pl *pl, const struct mbuf *mb)
  */
 int32_t pl_i32(const struct pl *pl)
 {
-	uint32_t v = 0;
+	int32_t v = 0;
 	uint32_t mul = 1;
 	const char *p;
 	bool neg = false;
@@ -76,7 +76,7 @@ int32_t pl_i32(const struct pl *pl)
 		const char ch = *--p;
 
 		if ('0' <= ch && ch <= '9') {
-			v += mul * (ch - '0');
+			v -= mul * (ch - '0');
 			mul *= 10;
 		}
 		else if (ch == '-' && p == pl->p) {
@@ -91,7 +91,10 @@ int32_t pl_i32(const struct pl *pl)
 		}
 	}
 
-	return neg ? -v : v;
+	if (!neg && v == INT32_MIN)
+		return INT32_MIN;
+
+	return neg ? v : -v;
 }
 
 
@@ -104,7 +107,7 @@ int32_t pl_i32(const struct pl *pl)
  */
 int64_t pl_i64(const struct pl *pl)
 {
-	uint64_t v = 0;
+	int64_t v = 0;
 	uint64_t mul = 1;
 	const char *p;
 	bool neg = false;
@@ -117,7 +120,7 @@ int64_t pl_i64(const struct pl *pl)
 		const char ch = *--p;
 
 		if ('0' <= ch && ch <= '9') {
-			v += mul * (ch - '0');
+			v -= mul * (ch - '0');
 			mul *= 10;
 		}
 		else if (ch == '-' && p == pl->p) {
@@ -132,7 +135,10 @@ int64_t pl_i64(const struct pl *pl)
 		}
 	}
 
-	return neg ? -v : v;
+	if (!neg && v == INT64_MIN)
+		return INT64_MIN;
+
+	return neg ? v : -v;
 }