ref: 7acd73fd6a6f34a2d40dfcbe47d18f5b5cb81888
parent: 660138753b036ea5fe14c55c1ee2a57ea7615431
author: David Turner <[email protected]>
date: Thu Jul 11 19:41:14 EDT 2002
* src/sfnt/ttload.c, src/sfnt/ttload.h, src/sfnt/ttdriver.c: changing
the SFNT loader to check for SFNT-based font files differently. We now
ignore the range "helper" fields and check the "head" table's magic
number instead.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,9 +1,17 @@
2002-07-11 David Turner <[email protected]>
+ * src/sfnt/ttload.c, src/sfnt/ttload.h, src/sfnt/ttdriver.c: changing
+ the SFNT loader to check for SFNT-based font files differently. We now
+ ignore the range "helper" fields and check the "head" table's magic
+ number instead.
+
+ * src/base/ftobject.c, src/base/fthash.c: updated object sub-system and
+ dynamic hash table implementation (still experimental, don't use)
+
* include/freetype/t1tables.h, include/freetype/internal/psaux.h,
src/psaux/psobjs.c, src/type1/t1load.c, src/type1/t1tokens.h:
fixing a bug in the Type 1 loader that prevented valid font bounding
- boxes to be loaded from multiple master fonts.
+ boxes to be loaded from multiple master fonts.
2002-07-10 David Turner <[email protected]>
--- a/include/freetype/internal/tttypes.h
+++ b/include/freetype/internal/tttypes.h
@@ -100,6 +100,8 @@
FT_UShort entry_selector;
FT_UShort range_shift;
+ FT_ULong offset; /* not in file */
+
} SFNT_HeaderRec, *SFNT_Header;
--- a/src/base/fthash.c
+++ b/src/base/fthash.c
@@ -197,7 +197,7 @@
num_buckets = ( table->p + table->mask + 1) ;
- if ( ++ table->slack > num_buckets*FT_HASH_SUB_LOAD )
+ if ( ++ table->slack > (FT_Long)num_buckets*FT_HASH_SUB_LOAD )
{FT_UInt p = table->p;
FT_UInt mask = table->mask;
--- a/src/base/ftobject.c
+++ b/src/base/ftobject.c
@@ -312,6 +312,7 @@
return (clazz == NULL);
}
+ return 0;
}
--- a/src/sfnt/sfdriver.c
+++ b/src/sfnt/sfdriver.c
@@ -251,7 +251,7 @@
SFNT_Get_Interface,
TT_Load_Any,
- TT_Load_SFNT_HeaderRec,
+ TT_Load_SFNT_Header,
TT_Load_Directory,
TT_Load_Header,
--- a/src/sfnt/ttload.c
+++ b/src/sfnt/ttload.c
@@ -135,6 +135,91 @@
}
+ /* in theory, we should check the values of `search_range', */
+ /* `entry_selector' and `range_shift' to detect non-SFNT based files */
+ /* whose header might also start with 0x100000L (yes, these exist). */
+ /* */
+ /* Very unfortunately, many TrueType fonts don't have these fields */
+ /* set correctly and we must ignore them to support them. An alternative */
+ /* way to check the font file is thus to: */
+ /* */
+ /* - check that `num_tables' is valid */
+ /* - look for a "head" table, check its size, and parse it to */
+ /* see if its "magic" field is correctly set to */
+ /* */
+ /* Voila, here comes robust though tolerant font format checking :-) */
+ /* */
+ static FT_Error
+ sfnt_dir_check( FT_Stream stream,
+ FT_ULong offset,
+ FT_UInt num_tables )
+ {+ FT_Error error;
+ FT_UInt nn;
+
+ static const FT_Frame_Field sfnt_dir_entry_fields[] =
+ {+#undef FT_STRUCTURE
+#define FT_STRUCTURE TT_TableRec
+
+ FT_FRAME_START( 16 ),
+ FT_FRAME_ULONG( Tag ),
+ FT_FRAME_ULONG( CheckSum ),
+ FT_FRAME_ULONG( Offset ),
+ FT_FRAME_ULONG( Length ),
+ FT_FRAME_END
+ };
+
+ /* if 'num_tables' is 0, read the table count from the file */
+ if ( num_tables == 0 )
+ {+ FT_ULong format_tag;
+
+ if ( FT_STREAM_SEEK( offset ) ||
+ FT_READ_ULONG ( format_tag ) ||
+ FT_READ_USHORT( num_tables ) ||
+ FT_STREAM_SKIP( 6 ) )
+ goto Bad_Format;
+
+ if ( offset + 12 + num_tables*16 > stream->size )
+ goto Bad_Format;
+ }
+ else if ( FT_STREAM_SEEK( offset + 12 ) )
+ goto Bad_Format;
+
+ for ( nn = 0; nn < num_tables; nn++ )
+ {+ TT_TableRec table;
+
+ if ( FT_STREAM_READ_FIELDS( sfnt_dir_entry_fields, &table ) )
+ goto Bad_Format;
+
+ if ( offset + table.Offset + table.Length > stream->size )
+ goto Bad_Format;
+
+ if ( table.Tag == TTAG_head )
+ {+ FT_UInt32 magic;
+
+ if ( table.Length != 0x36 ||
+ FT_STREAM_SEEK( offset + table.Offset + 12 ) ||
+ FT_READ_ULONG( magic ) ||
+ magic != 0x5F0F3CF5U )
+ goto Bad_Format;
+
+ if ( FT_STREAM_SEEK( offset + 28 + 16*nn ) )
+ goto Bad_Format;
+ }
+ }
+
+ Exit:
+ return error;
+
+ Bad_Format:
+ error = FT_Err_Unknown_File_Format;
+ goto Exit;
+ }
+
/*************************************************************************/
/* */
/* <Function> */
@@ -166,16 +251,16 @@
/* values of `search_range', `entry_selector', and `range_shift'. */
/* */
FT_LOCAL_DEF( FT_Error )
- TT_Load_SFNT_HeaderRec( TT_Face face,
- FT_Stream stream,
- FT_Long face_index,
- SFNT_Header sfnt )
+ TT_Load_SFNT_Header( TT_Face face,
+ FT_Stream stream,
+ FT_Long face_index,
+ SFNT_Header sfnt )
{FT_Error error;
- FT_ULong format_tag;
+ FT_ULong format_tag, offset;
FT_Memory memory = stream->memory;
- const FT_Frame_Field sfnt_header_fields[] =
+ static const FT_Frame_Field sfnt_header_fields[] =
{#undef FT_STRUCTURE
#define FT_STRUCTURE SFNT_HeaderRec
@@ -188,7 +273,7 @@
FT_FRAME_END
};
- const FT_Frame_Field ttc_header_fields[] =
+ static const FT_Frame_Field ttc_header_fields[] =
{#undef FT_STRUCTURE
#define FT_STRUCTURE TTC_HeaderRec
@@ -200,7 +285,7 @@
};
- FT_TRACE2(( "TT_Load_SFNT_HeaderRec: %08p, %ld\n",
+ FT_TRACE2(( "TT_Load_SFNT_Header: %08p, %ld\n",
face, face_index ));
face->ttc_header.tag = 0;
@@ -213,6 +298,8 @@
/* file is a TrueType collection, otherwise it can be any other */
/* kind of font. */
/* */
+ offset = FT_STREAM_POS();
+
if ( FT_READ_ULONG( format_tag ) )
goto Exit;
@@ -221,7 +308,7 @@
FT_Int n;
- FT_TRACE3(( "TT_Load_SFNT_HeaderRec: file is a collection\n" ));
+ FT_TRACE3(( "TT_Load_SFNT_Header: file is a collection\n" ));
/* It is a TrueType collection, i.e. a file containing several */
/* font files. Read the font directory now */
@@ -246,7 +333,9 @@
}
/* seek to the appropriate TrueType file, then read tag */
- if ( FT_STREAM_SEEK( face->ttc_header.offsets[face_index] ) ||
+ offset = face->ttc_header.offsets[ face_index ];
+
+ if ( FT_STREAM_SEEK( offset ) ||
FT_READ_LONG( format_tag ) )
goto Exit;
}
@@ -253,25 +342,17 @@
/* the format tag was read, now check the rest of the header */
sfnt->format_tag = format_tag;
+ sfnt->offset = offset;
+
if ( FT_STREAM_READ_FIELDS( sfnt_header_fields, sfnt ) )
goto Exit;
- /* now, check the values of `num_tables', `seach_range', etc. */
+ /* now check the sfnt directory */
+ error = sfnt_dir_check( stream, offset, sfnt->num_tables );
+ if ( error )
{- FT_UInt num_tables = sfnt->num_tables;
- FT_ULong entry_selector = 1L << sfnt->entry_selector;
-
-
- /* IMPORTANT: Many fonts have an incorrect `search_range' value, so */
- /* we only check the `entry_selector' correctness here. */
- /* */
- if ( num_tables == 0 ||
- entry_selector > num_tables ||
- entry_selector * 2 <= num_tables )
- {- FT_TRACE2(( "TT_Load_SFNT_HeaderRec: file is not SFNT!\n" ));
- error = SFNT_Err_Unknown_File_Format;
- }
+ FT_TRACE2(( "TT_Load_SFNT_Header: file is not SFNT!\n" ));
+ error = SFNT_Err_Unknown_File_Format;
}
Exit:
@@ -322,7 +403,8 @@
if ( FT_NEW_ARRAY( face->dir_tables, face->num_tables ) )
goto Exit;
- if ( FT_FRAME_ENTER( face->num_tables * 16L ) )
+ if ( FT_STREAM_SEEK( sfnt->offset + 12 ) ||
+ FT_FRAME_ENTER( face->num_tables * 16L ) )
goto Exit;
entry = face->dir_tables;
--- a/src/sfnt/ttload.h
+++ b/src/sfnt/ttload.h
@@ -41,10 +41,10 @@
FT_LOCAL( FT_Error )
- TT_Load_SFNT_HeaderRec( TT_Face face,
- FT_Stream stream,
- FT_Long face_index,
- SFNT_Header sfnt );
+ TT_Load_SFNT_Header( TT_Face face,
+ FT_Stream stream,
+ FT_Long face_index,
+ SFNT_Header sfnt );
FT_LOCAL( FT_Error )
TT_Load_Directory( TT_Face face,