Fix potential memory leak

cgohlke · web-flow · commit 5f329e3df171 · 2019-01-25T13:11:06.000-08:00
When realloc failed, the original pointer was lost (set to NULL).
diff --git a/src/_path.h b/src/_path.h
@@ -1053,12 +1053,14 @@ char *__append_to_string(char *p, char **buffer, size_t *buffersize,
             return NULL;
         }
         if ((size_t)(p - *buffer) >= *buffersize) {
+            char *newbuffer;
             ptrdiff_t diff = p - *buffer;
             *buffersize *= 2;
-            *buffer = (char *)realloc(*buffer, *buffersize);
-            if (*buffer == NULL) {
+            newbuffer = (char *)realloc(*buffer, *buffersize);
+            if (newbuffer == NULL) {
                 return NULL;
             }
+            *buffer = newbuffer;
             p = *buffer + diff;
         }
 

Original file line number	Diff line number	Diff line change
`@@ -1053,12 +1053,14 @@ char __append_to_string(char p, char *buffer, size_t buffersize,`
`1053`	`1053`	`return NULL;`
`1054`	`1054`	`}`
`1055`	`1055`	`if ((size_t)(p - buffer) >= buffersize) {`
	`1056`	`+ char *newbuffer;`
`1056`	`1057`	`ptrdiff_t diff = p - *buffer;`
`1057`	`1058`	`buffersize = 2;`
`1058`		`- buffer = (char )realloc(buffer, buffersize);`
`1059`		`- if (*buffer == NULL) {`
	`1059`	`+ newbuffer = (char )realloc(buffer, *buffersize);`
	`1060`	`+ if (newbuffer == NULL) {`
`1060`	`1061`	`return NULL;`
`1061`	`1062`	`}`
	`1063`	`+ *buffer = newbuffer;`
`1062`	`1064`	`p = *buffer + diff;`
`1063`	`1065`	`}`
`1064`	`1066`