code cleanup: remove redundant NULL checks and avoid writing to the source string.

also rename BLI_replacestr() -> BLI_replacestrN() since it returns an allocated buffer.

1 files changed, 18 insertions, 25 deletions

diff --git a/source/blender/blenlib/intern/string.c b/source/blender/blenlib/intern/string.c
index 3de57ccb54f..5bd07ac8778 100644
--- a/source/blender/blenlib/intern/string.c
+++ b/source/blender/blenlib/intern/string.c
@@ -305,34 +305,30 @@ char *BLI_str_quoted_substrN(const char *__restrict str, const char *__restrict
 }
 
 /**
+ * string with all instances of substr_old replaced with substr_new,
  * Returns a copy of the cstring \a str into a newly mallocN'd
- * string with all instances of oldText replaced with newText,
  * and returns it.
  *
  * \note A rather wasteful string-replacement utility, though this shall do for now...
  * Feel free to replace this with an even safe + nicer alternative
  *
- * \param str The string to replace occurrences of oldText in
- * \param oldText The text in the string to find and replace
- * \param newText The text in the string to find and replace
+ * \param str The string to replace occurrences of substr_old in
+ * \param substr_old The text in the string to find and replace
+ * \param substr_new The text in the string to find and replace
  * \retval Returns the duplicated string
  */
-char *BLI_replacestr(char *__restrict str, const char *__restrict oldText, const char *__restrict newText)
+char *BLI_replacestrN(const char *__restrict str, const char *__restrict substr_old, const char *__restrict substr_new)
 {
 	DynStr *ds = NULL;
-	size_t lenOld = strlen(oldText);
-	char *match;
-	
-	/* sanity checks */
-	if ((str == NULL) || (str[0] == 0))
-		return NULL;
-	else if ((oldText == NULL) || (newText == NULL) || (oldText[0] == 0))
-		return BLI_strdup(str);
-	
+	size_t len_old = strlen(substr_old);
+	const char *match;
+
+	BLI_assert(substr_old[0] != '\0');
+
 	/* while we can still find a match for the old substring that we're searching for, 
 	 * keep dicing and replacing
 	 */
-	while ( (match = strstr(str, oldText)) ) {
+	while ((match = strstr(str, substr_old))) {
 		/* the assembly buffer only gets created when we actually need to rebuild the string */
 		if (ds == NULL)
 			ds = BLI_dynstr_new();
@@ -341,27 +337,24 @@ char *BLI_replacestr(char *__restrict str, const char *__restrict oldText, const
 		 * copy the text up to this position and advance the current position in the string
 		 */
 		if (str != match) {
-			/* replace the token at the 'match' position with \0 so that the copied string will be ok,
-			 * add the segment of the string from str to match to the buffer, then restore the value at match
+			/* add the segment of the string from str to match to the buffer, then restore the value at match
 			 */
-			match[0] = 0;
-			BLI_dynstr_append(ds, str);
-			match[0] = oldText[0];
+			BLI_dynstr_nappend(ds, str, (match - str));
 			
 			/* now our current position should be set on the start of the match */
 			str = match;
 		}
 		
 		/* add the replacement text to the accumulation buffer */
-		BLI_dynstr_append(ds, newText);
+		BLI_dynstr_append(ds, substr_new);
 		
 		/* advance the current position of the string up to the end of the replaced segment */
-		str += lenOld;
+		str += len_old;
 	}
 	
 	/* finish off and return a new string that has had all occurrences of */
 	if (ds) {
-		char *newStr;
+		char *str_new;
 		
 		/* add what's left of the string to the assembly buffer 
 		 *	- we've been adjusting str to point at the end of the replaced segments
@@ -370,10 +363,10 @@ char *BLI_replacestr(char *__restrict str, const char *__restrict oldText, const
 			BLI_dynstr_append(ds, str);
 		
 		/* convert to new c-string (MEM_malloc'd), and free the buffer */
-		newStr = BLI_dynstr_get_cstring(ds);
+		str_new = BLI_dynstr_get_cstring(ds);
 		BLI_dynstr_free(ds);
 		
-		return newStr;
+		return str_new;
 	}
 	else {
 		/* just create a new copy of the entire string - we avoid going through the assembly buffer