From 58b61b6e05597112f8673e5ab9bd175f59e2db5e Mon Sep 17 00:00:00 2001
From: Werner Lemberg <wl@gnu.org>
Date: Tue, 13 Oct 2015 18:26:18 +0200
Subject: [PATCH] [pcf] Quickly exit if font index < 0.

Similar to other font formats, this commit makes the parser no
longer check the whole PCF file but only the header and the TOC if
we just want to get the number of available faces (and a proper
recognition of the font format).

* src/pcf/pcfdrivr.c (PCF_Face_Init): Updated.
Exit quickly if face_index < 0.

* src/pcfread.c (pcf_load_font): Add `face_index' argument.
Exit quickly if face_index < 0.

* src/pcf/pcf.h: Updated.
---
 ChangeLog          | 17 +++++++++++++++++
 src/pcf/pcf.h      |  5 +++--
 src/pcf/pcfdrivr.c |  8 +++++---
 src/pcf/pcfread.c  | 15 ++++++++++-----
 4 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index b8a99e2ab..aa5c7b545 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,20 @@
+2015-10-13  Werner Lemberg  <wl@gnu.org>
+
+	[pcf] Quickly exit if font index < 0.
+
+	Similar to other font formats, this commit makes the parser no
+	longer check the whole PCF file but only the header and the TOC if
+	we just want to get the number of available faces (and a proper
+	recognition of the font format).
+
+	* src/pcf/pcfdrivr.c (PCF_Face_Init): Updated.
+	Exit quickly if face_index < 0.
+
+	* src/pcfread.c (pcf_load_font): Add `face_index' argument.
+	Exit quickly if face_index < 0.
+
+	* src/pcf/pcf.h: Updated.
+
 2015-10-13  Werner Lemberg  <wl@gnu.org>
 
 	[ftfuzzer] Handle TTCs and MM/GX variations.
diff --git a/src/pcf/pcf.h b/src/pcf/pcf.h
index c0da50341..253a33f73 100644
--- a/src/pcf/pcf.h
+++ b/src/pcf/pcf.h
@@ -226,8 +226,9 @@ FT_BEGIN_HEADER
 #define GLYPHPADOPTIONS  4 /* I'm not sure about this */
 
   FT_LOCAL( FT_Error )
-  pcf_load_font( FT_Stream,
-                 PCF_Face );
+  pcf_load_font( FT_Stream  stream,
+                 PCF_Face   face,
+                 FT_Long    face_index );
 
 FT_END_HEADER
 
diff --git a/src/pcf/pcfdrivr.c b/src/pcf/pcfdrivr.c
index 8d2ed7cf4..0f4c51828 100644
--- a/src/pcf/pcfdrivr.c
+++ b/src/pcf/pcfdrivr.c
@@ -271,7 +271,7 @@ THE SOFTWARE.
 
     FT_TRACE2(( "PCF driver\n" ));
 
-    error = pcf_load_font( stream, face );
+    error = pcf_load_font( stream, face, face_index );
     if ( error )
     {
       PCF_Face_Done( pcfface );
@@ -332,7 +332,7 @@ THE SOFTWARE.
 
       stream = pcfface->stream;
 
-      error = pcf_load_font( stream, face );
+      error = pcf_load_font( stream, face, face_index );
       if ( error )
         goto Fail;
 
@@ -351,7 +351,9 @@ THE SOFTWARE.
      *      an invalid argument error when the font could be
      *      opened by the specified driver.
      */
-    if ( face_index > 0 && ( face_index & 0xFFFF ) > 0 )
+    if ( face_index < 0 )
+      goto Exit;
+    else if ( face_index > 0 && ( face_index & 0xFFFF ) > 0 )
     {
       FT_ERROR(( "PCF_Face_Init: invalid face index\n" ));
       PCF_Face_Done( pcfface );
diff --git a/src/pcf/pcfread.c b/src/pcf/pcfread.c
index 6a248cfcc..fca677f4f 100644
--- a/src/pcf/pcfread.c
+++ b/src/pcf/pcfread.c
@@ -1184,8 +1184,10 @@ THE SOFTWARE.
 
   FT_LOCAL_DEF( FT_Error )
   pcf_load_font( FT_Stream  stream,
-                 PCF_Face   face )
+                 PCF_Face   face,
+                 FT_Long    face_index )
   {
+    FT_Face    root   = FT_FACE( face );
     FT_Error   error;
     FT_Memory  memory = FT_FACE( face )->memory;
     FT_Bool    hasBDFAccelerators;
@@ -1195,6 +1197,13 @@ THE SOFTWARE.
     if ( error )
       goto Exit;
 
+    root->num_faces  = 1;
+    root->face_index = 0;
+
+    /* If we are performing a simple font format check, exit immediately. */
+    if ( face_index < 0 )
+      return FT_Err_Ok;
+
     error = pcf_get_properties( stream, face );
     if ( error )
       goto Exit;
@@ -1237,13 +1246,9 @@ THE SOFTWARE.
 
     /* now construct the face object */
     {
-      FT_Face       root = FT_FACE( face );
       PCF_Property  prop;
 
 
-      root->num_faces  = 1;
-      root->face_index = 0;
-
       root->face_flags |= FT_FACE_FLAG_FIXED_SIZES |
                           FT_FACE_FLAG_HORIZONTAL  |
                           FT_FACE_FLAG_FAST_GLYPHS;