Fri Mar 15 01:35:56 2002  Owen Taylor  <otaylor@redhat.com>

        * pango/opentype/ftxgsub.c pango/opentype/ftxopen.c
        pango/opentype/ftxopenf.h: In Load_ChainContextSubst2,
        handle the case where an empty class definition
        is represented by an offset of 0.
 
        * pango/opentype/ftxgpos.c: Same for Load_ChainContextPos2.
 
Index: ftxgpos.c
===================================================================
RCS file: /cvs/gnome/pango/pango/opentype/ftxgpos.c,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -p -r1.3 -r1.4
--- ftxgpos.c	19 Sep 2001 21:20:36 -0000	1.3
+++ ftxgpos.c	15 Mar 2002 06:46:05 -0000	1.4
@@ -4724,6 +4769,30 @@
   }
 
 
+  static FT_Error Load_EmptyOrClassDefinition( TTO_ClassDefinition*  cd,
+                                               FT_UShort             limit,
+					       FT_ULong              class_offset,
+					       FT_ULong              base_offset,
+				               FT_Stream             stream )
+  {
+    FT_Error error;
+    FT_ULong               cur_offset;
+
+    cur_offset = FILE_Pos();
+
+    if ( class_offset )
+      {
+        if ( !FILE_Seek( class_offset + base_offset ) )
+          error = Load_ClassDefinition( cd, limit, stream ) == TT_Err_Ok;
+      }
+    else
+       error = Load_EmptyClassDefinition ( cd, stream );
+
+    (void)FILE_Seek( cur_offset );
+
+    return error;
+  }
+
   /* ChainContextPosFormat2 */
 
   static FT_Error  Load_ChainContextPos2( TTO_ChainContextPosFormat2*  ccpf2,
@@ -4768,20 +4837,18 @@
 
     FORGET_Frame();
 
-    cur_offset = FILE_Pos();
-    if ( FILE_Seek( backtrack_offset ) ||
-         ( error = Load_ClassDefinition( &ccpf2->BacktrackClassDef, count,
-                                         stream ) ) != TT_Err_Ok )
+    if ( ( error = Load_EmptyOrClassDefinition( &ccpf2->BacktrackClassDef, count,
+						backtrack_offset, base_offset,
+						stream ) ) != TT_Err_Ok )
       goto Fail5;
-    if ( FILE_Seek( input_offset ) ||
-         ( error = Load_ClassDefinition( &ccpf2->InputClassDef, count,
-                                         stream ) ) != TT_Err_Ok )
+    if ( ( error = Load_EmptyOrClassDefinition( &ccpf2->InputClassDef, count,
+						input_offset, base_offset,
+						stream ) ) != TT_Err_Ok )
       goto Fail4;
-    if ( FILE_Seek( lookahead_offset ) ||
-         ( error = Load_ClassDefinition( &ccpf2->LookaheadClassDef, count,
-                                         stream ) ) != TT_Err_Ok )
+    if ( ( error = Load_EmptyOrClassDefinition( &ccpf2->LookaheadClassDef, count,
+						lookahead_offset, base_offset,
+						stream ) ) != TT_Err_Ok )
       goto Fail3;
-    (void)FILE_Seek( cur_offset );
 
     ccpf2->ChainPosClassSet   = NULL;
     ccpf2->MaxBacktrackLength = 0;
Index: ftxgsub.c
===================================================================
RCS file: /cvs/gnome/pango/pango/opentype/ftxgsub.c,v
retrieving revision 1.2
retrieving revision 1.3
diff -u -p -r1.2 -r1.3
--- ftxgsub.c	19 Sep 2001 21:20:36 -0000	1.2
+++ ftxgsub.c	15 Mar 2002 06:46:05 -0000	1.3
@@ -2943,6 +2943,30 @@
     }
   }
 
+  static FT_Error Load_EmptyOrClassDefinition( TTO_ClassDefinition*  cd,
+                                               FT_UShort             limit,
+					       FT_ULong              class_offset,
+					       FT_ULong              base_offset,
+				               FT_Stream             stream )
+  {
+    FT_Error error;
+    FT_ULong               cur_offset;
+
+    cur_offset = FILE_Pos();
+
+    if ( class_offset )
+      {
+        if ( !FILE_Seek( class_offset + base_offset ) )
+          error = Load_ClassDefinition( cd, limit, stream ) == TT_Err_Ok;
+      }
+    else
+       error = Load_EmptyClassDefinition ( cd, stream );
+
+    (void)FILE_Seek( cur_offset );
+
+    return error;
+  }
+
 
   /* ChainContextSubstFormat2 */
 
@@ -2989,20 +3013,19 @@
 
     FORGET_Frame();
 
-    cur_offset = FILE_Pos();
-    if ( FILE_Seek( backtrack_offset ) ||
-         ( error = Load_ClassDefinition( &ccsf2->BacktrackClassDef, count,
-                                         stream ) ) != TT_Err_Ok )
-      goto Fail5;
-    if ( FILE_Seek( input_offset ) ||
-         ( error = Load_ClassDefinition( &ccsf2->InputClassDef, count,
-                                         stream ) ) != TT_Err_Ok )
-      goto Fail4;
-    if ( FILE_Seek( lookahead_offset ) ||
-         ( error = Load_ClassDefinition( &ccsf2->LookaheadClassDef, count,
-                                         stream ) ) != TT_Err_Ok )
+    if ( ( error = Load_EmptyOrClassDefinition( &ccsf2->BacktrackClassDef, count,
+                                                backtrack_offset, base_offset,
+					        stream ) ) != TT_Err_Ok )
+        goto Fail5;
+	       
+    if ( ( error = Load_EmptyOrClassDefinition( &ccsf2->InputClassDef, count,
+                                                input_offset, base_offset,
+                                                stream ) ) != TT_Err_Ok )
+        goto Fail4;
+    if ( ( error = Load_EmptyOrClassDefinition( &ccsf2->LookaheadClassDef, count,
+                                                lookahead_offset, base_offset,
+                                                stream ) ) != TT_Err_Ok )
       goto Fail3;
-    (void)FILE_Seek( cur_offset );
 
     ccsf2->ChainSubClassSet   = NULL;
     ccsf2->MaxBacktrackLength = 0;
Index: ftxopen.c
===================================================================
RCS file: /cvs/gnome/pango/pango/opentype/ftxopen.c,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -p -r1.4 -r1.5
--- ftxopen.c	15 Mar 2002 04:22:14 -0000	1.4
+++ ftxopen.c	15 Mar 2002 06:46:05 -0000	1.5
@@ -1199,6 +1199,29 @@
     return error;
   }
 
+
+  FT_Error  Load_EmptyClassDefinition( TTO_ClassDefinition*  cd,
+				       FT_Stream             stream )
+  {
+    FT_Error   error;
+    FT_Memory  memory = stream->memory;
+
+
+    if ( ALLOC_ARRAY( cd->Defined, 1, FT_Bool ) )
+      return error;
+
+    cd->ClassFormat = 1; /* Meaningless */
+    cd->Defined[0] = FALSE;
+
+    if ( ALLOC_ARRAY( cd->cd.cd1.ClassValueArray, 1, FT_UShort ) )
+      goto Fail;
+
+    return TT_Err_Ok;
+
+  Fail:
+    FREE( cd->Defined );
+    return error;
+  }
 
   void  Free_ClassDefinition( TTO_ClassDefinition*  cd,
 			      FT_Memory             memory )
Index: ftxopenf.h
===================================================================
RCS file: /cvs/gnome/pango/pango/opentype/ftxopenf.h,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -p -r1.1 -r1.2
--- ftxopenf.h	20 Dec 2000 04:41:36 -0000	1.1
+++ ftxopenf.h	15 Mar 2002 06:46:05 -0000	1.2
@@ -39,6 +39,8 @@ extern "C" {
   FT_Error  Load_ClassDefinition( TTO_ClassDefinition*  cd,
                                   FT_UShort             limit,
                                   FT_Stream             input );
+  FT_Error  Load_EmptyClassDefinition( TTO_ClassDefinition*  cd,
+                                       FT_Stream             input );
   FT_Error  Load_Device( TTO_Device*  d,
                          FT_Stream    input );