iniRenameSection() returns FALSE if attempting to rename to an existing

(duplicate) section name.

src/xpdev/ini_file.c

@@ -280,6 +280,10 @@ BOOL iniRenameSection(str_list_t* list, const char* section, const char* newname
 	if(section==ROOT_SECTION)
 		return(FALSE);
 
+	i=find_section_index(*list,newname);
+	if((*list)[i]!=NULL)	/* duplicate */
+		return(FALSE);
+
 	i=find_section_index(*list,section);
 	if((*list)[i]==NULL)	/* not found */
 		return(FALSE);