[base] Don't zero out allocated memory twice (#51816).

Patch applied from bug report.

* src/base/ftutil.c (ft_mem_qrealloc): Use low-level allocation to
avoid unnecessary overhead.

ChangeLog

@@ -1,3 +1,12 @@
+2017-08-22  Werner Lemberg  <wl@gnu.org>
+
+	[base] Don't zero out allocated memory twice (#51816).
+
+	Patch applied from bug report.
+
+	* src/base/ftutil.c (ft_mem_qrealloc): Use low-level allocation to
+	avoid unnecessary overhead.
+
 2017-08-22  Werner Lemberg  <wl@gnu.org>
 
 	[truetype] Integer overflow.

src/base/ftutil.c

@@ -135,7 +135,7 @@
       ft_mem_free( memory, block );
       block = NULL;
     }
-    else if ( new_count > FT_INT_MAX/item_size )
+    else if ( new_count > FT_INT_MAX / item_size )
     {
       error = FT_THROW( Array_Too_Large );
     }
@@ -143,13 +143,15 @@
     {
       FT_ASSERT( !block );
 
-      block = ft_mem_alloc( memory, new_count*item_size, &error );
+      block = memory->alloc( memory, new_count * item_size );
+      if ( block == NULL )
+        error = FT_THROW( Out_Of_Memory );
     }
     else
     {
       FT_Pointer  block2;
-      FT_Long     cur_size = cur_count*item_size;
-      FT_Long     new_size = new_count*item_size;
+      FT_Long     cur_size = cur_count * item_size;
+      FT_Long     new_size = new_count * item_size;
 
 
       block2 = memory->realloc( memory, cur_size, new_size, block );