--- a/tools/lib64gfx.c	Thu May 10 21:57:20 2018 +0300
+++ b/tools/lib64gfx.c	Thu May 10 22:30:02 2018 +0300
@@ -1350,7 +1350,7 @@
 {
     int res = DMERR_OK;
 
-    if (buf == NULL || img == NULL || fmt == NULL)
+    if (img == NULL || fmt == NULL)
         return DMERR_NULLPTR;
 
     // Allocate the output buffer
@@ -1361,6 +1361,7 @@
             fmt->size);
         goto err;
     }
+    buf->len = fmt->size;
 
     // Perform encoding
     for (int i = 0; i < D64_MAX_ENCDEC_OPS; i++)
@@ -1725,15 +1726,18 @@
         goto err;
 
     // Add the loading address
-    if ((res = dmGrowBufGrow(buf, 2)) != DMERR_OK)
+    if (!dmGrowBufGrow(buf, 2))
+    {
+        res = DMERR_MALLOC;
         goto err;
+    }
 
     memmove(buf->data + 2, buf->data, buf->len);
 
     buf->data[0] = DM_GET_ADDR_LO(fmt->addr);
     buf->data[1] = DM_GET_ADDR_HI(fmt->addr);
 
-    buf->len += 2;
+    return DMERR_OK;
 
 err:
     dmGrowBufFree(buf);