[truetype] Better tracing of composite glyphs.

* src/truetype/ttgload.c (TT_Load_Composite_Glyph,
load_truetype_glyph): Implement it.

ChangeLog

@@ -1,3 +1,10 @@
+2015-11-04  Werner Lemberg  <wl@gnu.org>
+
+	[truetype] Better tracing of composite glyphs.
+
+	* src/truetype/ttgload.c (TT_Load_Composite_Glyph,
+	load_truetype_glyph): Implement it.
+
 2015-11-03  Werner Lemberg  <wl@gnu.org>
 
 	[sfnt] Protect against zero-size bitmaps (#46345).

src/truetype/ttgload.c

@@ -659,6 +659,7 @@
     } while ( subglyph->flags & MORE_COMPONENTS );
 
     gloader->current.num_subglyphs = num_subglyphs;
+    FT_TRACE5(( "  %d components\n", num_subglyphs ));
 
 #ifdef TT_USE_BYTECODE_INTERPRETER
 
@@ -1395,6 +1396,11 @@
 #endif
 
 
+#ifdef FT_DEBUG_LEVEL_TRACE
+    if ( recurse_count )
+      FT_TRACE5(( "  nesting level: %d\n", recurse_count ));
+#endif
+
     /* some fonts have an incorrect value of `maxComponentDepth', */
     /* thus we allow depth 1 to catch the majority of them        */
     if ( recurse_count > 1                                   &&