Diff: SW_String.cpp

Revision:

3:bc30d348f5b4

Parent:

2:c7a3039893cb

diff -r c7a3039893cb -r bc30d348f5b4 SW_String.cpp
--- a/SW_String.cpp	Sun Nov 18 04:04:48 2018 +0000
+++ b/SW_String.cpp	Wed Feb 27 18:22:04 2019 +0000
@@ -43,16 +43,22 @@
     }
     if (src == NULL || *src == '\0')
         return 0;       // done, that was easy.
-    if (src >= dst && src <= dst + dstSize) {
+    //            [Source .... 
+    //  [Destination  ... ]
+    if (src >= dst && src < (dst + dstSize)) {
         ERR("strcat_s FAIL source overlaps destination");
         return -3;
     }
     int dstLen = strlen(dst);
     int srcLen = strlen(src);
+    //          [Source ..... +srcLen]
+    //  [Destination                  + dstSize]
     if (src + srcLen >= dst && src + srcLen <= dst + dstSize) {
         ERR("strcat_s FAIL source + length overlaps destination");
         return -3;
     }
+    //                                   [Source length > freespace]
+    //  [Destination   ... \0[freespace]]
     if (dstLen + srcLen > dstSize) {
         ERR("strcat_s FAIL dstLen + srcLen > size");
         return -2;
@@ -91,7 +97,7 @@
         *dst = '\0';
         return 0;       // done, that was easy.
     }
-    if (src >= dst && src <= dst + dstSize) {
+    if (src >= dst && src < dst + dstSize) {
         ERR("strcpy_s FAIL source overlaps destination");
         return -3;
     }