# HG changeset patch
# User Matti Hamalainen <ccr@tnsp.org>
# Date 1529674407 -10800
# Node ID ce1a734b016f8166f7d408ba6bb9287afe0ef2bf
# Parent  3d4bb20f6739b727485284c33022c3a83bdc6b3b
Change the logic of how DMGrowBuf works in "backwards" growing mode. Adjust
the code that uses this as well.

diff -r 3d4bb20f6739 -r ce1a734b016f src/dmgrowbuf.c
--- a/src/dmgrowbuf.c	Fri Jun 22 16:17:06 2018 +0300
+++ b/src/dmgrowbuf.c	Fri Jun 22 16:33:27 2018 +0300
@@ -256,13 +256,13 @@
     {
         if (buf->literal)
         {
-            buf->offs -= len;
-            memcpy(buf->data + buf->offs, data, len);
+            for (size_t n = 0; n < len; n++)
+                buf->data[--buf->offs] = data[len - n];
         }
         else
         {
             for (size_t n = 0; n < len; n++)
-                buf->data[buf->offs--] = data[n];
+                buf->data[--buf->offs] = data[n];
         }
     }
     else
@@ -280,11 +280,10 @@
     if (!dmGrowBufGrow(buf, sizeof(Uint8)))
         return FALSE;
 
-    buf->data[buf->offs] = value;
     if (buf->backwards)
-        buf->offs--;
+        buf->data[--buf->offs] = value;
     else
-        buf->offs++;
+        buf->data[buf->offs++] = value;
 
     return TRUE;
 }
@@ -371,7 +370,7 @@
     if (buf->backwards)
     {
         if (buf->offs > 0)
-            *value = buf->data[buf->offs--];
+            *value = buf->data[--buf->offs];
         else
             return FALSE;
     }
diff -r 3d4bb20f6739 -r ce1a734b016f tools/lib64gfx.c
--- a/tools/lib64gfx.c	Fri Jun 22 16:17:06 2018 +0300
+++ b/tools/lib64gfx.c	Fri Jun 22 16:33:27 2018 +0300
@@ -385,14 +385,14 @@
 {
     if (cfg->flags & DM_RLE_BACKWARDS_INPUT)
     {
-        src->offs = src->len - 1;
+        src->offs = src->len;
         src->backwards = TRUE;
     }
 
     if (cfg->flags & DM_RLE_BACKWARDS_OUTPUT)
     {
         dst->backwards = TRUE;
-        dst->offs = dst->size - 1;
+        dst->offs = dst->size;
     }
 }
 
@@ -412,7 +412,7 @@
         case DM_OUT_CROP_END:
             if (cfg->cropOutLen < dst->len)
             {
-                memmove(dst->data, dst->data + dst->len - cfg->cropOutLen + 1, cfg->cropOutLen - 1);
+                memmove(dst->data, dst->data + dst->len - cfg->cropOutLen, cfg->cropOutLen);
                 dst->len = cfg->cropOutLen;
             }
             break;