fixed #395 heap corruption in nk_buffer

CHANGELOG.md

@@ -11,6 +11,7 @@
 
 Changes:
 --------
+- 2017/04/09 (1.35.3) - Fixed buffer heap corruption
 - 2017/03/25 (1.35.2) - Fixed popup overlapping for `NK_WINDOW_BACKGROUND` windows
 - 2017/03/25 (1.35.1) - Fixed windows closing behavior
 - 2017/03/18 (1.35.0) - Added horizontal scroll requested in #377

nuklear.h

@@ -5468,7 +5468,7 @@ nk_buffer_alloc(struct nk_buffer *b, enum nk_buffer_allocation_type type,
     /* check if buffer has enough memory*/
     if (type == NK_BUFFER_FRONT)
         full = ((b->allocated + size + alignment) > b->size);
-    else full = ((b->size - (size + alignment)) <= b->allocated);
+    else full = ((b->size - NK_MIN(b->size,(size + alignment))) <= b->allocated);
 
     if (full) {
         nk_size capacity;