Fix strswab() to reliably find end of string

Patch by Andrew Dyer, 08 Feb 2005

Fix strswab() to reliably find end of string
Patch by Andrew Dyer, 08 Feb 2005
Wolfgang Denk
1 parent 6ed6ce62be
Showing 2 changed files with 9 additions and 5 deletions Side-by-side Diff
CHANGELOG
lib_generic/string.c
@@ -2,6 +2,9 @@
 Changes for U-Boot 1.1.4:
 ======================================================================
  
+* Fix strswab() to reliably find end of string
+  Patch by Andrew Dyer, 08 Feb 2005
+
 * Fix typos in include/ppc440.h
   Patch by Andrew E Mileski, 04 Feb 2005
  
@@ -374,17 +374,18 @@
  */
 char *strswab(const char *s)
 {
-	char *p;
+	char *p, *q;
  
 	if ((NULL == s) || ('\0' == *s)) {
 		return (NULL);
 	}
  
-	for (p = ((char *)s + 1); '\0' != *p; p += 2) {
+	for (p=(char *)s, q=p+1; (*p != '\0') && (*p != '\0'); p+=2, q+=2) {
 		char  tmp;
-		tmp = *(p-1);
-		*(p-1) = *p;
-		*p = tmp;
+
+		tmp = *p;
+		*p  = *q;
+		*q  = tmp;
 	}
  
 	return (char *) s;
...	...	@@ -2,6 +2,9 @@
2	2	Changes for U-Boot 1.1.4:
3	3	======================================================================
4	4
	5	+* Fix strswab() to reliably find end of string
	6	+ Patch by Andrew Dyer, 08 Feb 2005
	7	+
5	8	* Fix typos in include/ppc440.h
6	9	Patch by Andrew E Mileski, 04 Feb 2005
7	10
...	...	@@ -374,17 +374,18 @@
374	374	*/
375	375	char strswab(const char s)
376	376	{
377		- char *p;
	377	+ char p, q;
378	378
379	379	if ((NULL == s) \|\| ('\0' == *s)) {
380	380	return (NULL);
381	381	}
382	382
383		- for (p = ((char )s + 1); '\0' != p; p += 2) {
	383	+ for (p=(char )s, q=p+1; (p != '\0') && (*p != '\0'); p+=2, q+=2) {
384	384	char tmp;
385		- tmp = *(p-1);
386		- (p-1) = p;
387		- *p = tmp;
	385	+
	386	+ tmp = *p;
	387	+ p = q;
	388	+ *q = tmp;
388	389	}
389	390
390	391	return (char *) s;