1 files changed, 8 insertions, 3 deletions

diff --git a/libbb/safe_strncpy.c b/libbb/safe_strncpy.c
index 8eb6a014f..5eb0db0bd 100644
--- a/libbb/safe_strncpy.c
+++ b/libbb/safe_strncpy.c
@@ -20,8 +20,13 @@ char* FAST_FUNC safe_strncpy(char *dst, const char *src, size_t size)
 /* Like strcpy but can copy overlapping strings. */
 void FAST_FUNC overlapping_strcpy(char *dst, const char *src)
 {
-        while ((*dst = *src) != '\0') {
-                dst++;
-                src++;
+        /* Cheap optimization for dst == src case -
+         * better to have it here than in many callers.
+         */
+        if (dst != src) {
+                while ((*dst = *src) != '\0') {
+                        dst++;
+                        src++;
+                }
         }
 }