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[pcf] Fix handling of undefined glyph (#56067). 

This commit fixes the changes from 2018-07-21, which broke charmap
iteration.  We now add the default character as a new glyph with
index 0, thus increasing the number of glyphs by one (as before).

* src/pcf/pcfread.c (pcf_get_metrics): Adjust to new artificial
glyph with index 0.
Limit number of elements to 65534.
(pcf_get_bitmaps): Ditto.
Unify two loops into one; this avoids allocation of an intermediate
array.
(pcf_get_encodings): Don't flip indices but copy glyph metrics of
default character to index 0.
Also handle invalid default character.

* docs/CHANGES: Updated.
This commit is contained in:
Werner Lemberg 2019-04-17 07:49:17 +02:00
parent ebe3750812
commit c149f7397e
5 changed files with 117 additions and 83 deletions
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20
ChangeLog
View File

@ -1,3 +1,23 @@
2019-04-18 Werner Lemberg <wl@gnu.org>
[pcf] Fix handling of undefined glyph (#56067).
This commit fixes the changes from 2018-07-21, which broke charmap
iteration. We now add the default character as a new glyph with
index 0, thus increasing the number of glyphs by one (as before).
* src/pcf/pcfread.c (pcf_get_metrics): Adjust to new artificial
glyph with index 0.
Limit number of elements to 65534.
(pcf_get_bitmaps): Ditto.
Unify two loops into one; this avoids allocation of an intermediate
array.
(pcf_get_encodings): Don't flip indices but copy glyph metrics of
default character to index 0.
Also handle invalid default character.
* docs/CHANGES: Updated.
2019-04-15 Minmin Gong <gongminmin@msn.com> 2019-04-15 Minmin Gong <gongminmin@msn.com>
* CMakeLists.txt: Avoid rewriting of unchanged configuration files. * CMakeLists.txt: Avoid rewriting of unchanged configuration files.

4
docs/CHANGES
View File

@ -11,6 +11,10 @@ CHANGES BETWEEN 2.10.0 and 2.10.1
- For distribution, `.tar.bz2' packages are replaced with `.tar.xz' - For distribution, `.tar.bz2' packages are replaced with `.tar.xz'
bundles. bundles.
- The handling of the default character in PCF fonts as introduced
in version 2.9.1 was partially broken, causing premature abortion
of charmap iteration for many fonts.
====================================================================== ======================================================================

3
src/pcf/pcf.h
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@ -99,7 +99,8 @@ FT_BEGIN_HEADER
FT_Short ascent; FT_Short ascent;
FT_Short descent; FT_Short descent;
FT_Short attributes; FT_Short attributes;
FT_ULong bits;
FT_ULong bits; /* offset into the PCF_BITMAPS table */
} PCF_MetricRec, *PCF_Metric; } PCF_MetricRec, *PCF_Metric;

12
src/pcf/pcfdrivr.c
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@ -122,9 +122,9 @@ THE SOFTWARE.
charcodeCol > enc->lastCol ) charcodeCol > enc->lastCol )
return 0; return 0;
return (FT_UInt)enc->offset[ ( charcodeRow - enc->firstRow ) * return (FT_UInt)enc->offset[( charcodeRow - enc->firstRow ) *
( enc->lastCol - enc->firstCol + 1 ) + ( enc->lastCol - enc->firstCol + 1 ) +
charcodeCol - enc->firstCol ]; charcodeCol - enc->firstCol];
} }
@ -160,9 +160,9 @@ THE SOFTWARE.
charcode = (FT_UInt32)( charcodeRow * 256 + charcodeCol ); charcode = (FT_UInt32)( charcodeRow * 256 + charcodeCol );
result = (FT_UInt)enc->offset[ ( charcodeRow - enc->firstRow ) * result = (FT_UInt)enc->offset[( charcodeRow - enc->firstRow ) *
( enc->lastCol - enc->firstCol + 1 ) + ( enc->lastCol - enc->firstCol + 1 ) +
charcodeCol - enc->firstCol ]; charcodeCol - enc->firstCol];
if ( result != 0xFFFFU ) if ( result != 0xFFFFU )
break; break;
} }

161
src/pcf/pcfread.c
View File

@ -743,33 +743,39 @@ THE SOFTWARE.
if ( !orig_nmetrics ) if ( !orig_nmetrics )
return FT_THROW( Invalid_Table ); return FT_THROW( Invalid_Table );
/* PCF is a format from ancient times; Unicode was in its */ /*
/* infancy, and widely used two-byte character sets for CJK */ * PCF is a format from ancient times; Unicode was in its infancy, and
/* scripts (Big 5, GB 2312, JIS X 0208, etc.) did have at most */ * widely used two-byte character sets for CJK scripts (Big 5, GB 2312,
/* 15000 characters. Even the more exotic CNS 11643 and CCCII */ * JIS X 0208, etc.) did have at most 15000 characters. Even the more
/* standards, which were essentially three-byte character sets, */ * exotic CNS 11643 and CCCII standards, which were essentially
/* provided less then 65536 assigned characters. */ * three-byte character sets, provided less then 65536 assigned
/* */ * characters.
/* While technically possible to have a larger number of glyphs */ *
/* in PCF files, we thus limit the number to 65536. */ * While technically possible to have a larger number of glyphs in PCF
if ( orig_nmetrics > 65536 ) * files, we thus limit the number to 65535, taking into account that we
* synthesize the metrics of glyph 0 to be a copy of the `default
* character', and that 0xFFFF in the encodings array indicates a
* missing glyph.
*/
if ( orig_nmetrics > 65534 )
{ {
FT_TRACE0(( "pcf_get_metrics:" FT_TRACE0(( "pcf_get_metrics:"
" only loading first 65536 metrics\n" )); " only loading first 65534 metrics\n" ));
nmetrics = 65536; nmetrics = 65534;
} }
else else
nmetrics = orig_nmetrics; nmetrics = orig_nmetrics;
face->nmetrics = nmetrics; face->nmetrics = nmetrics + 1;
if ( FT_NEW_ARRAY( face->metrics, nmetrics ) ) if ( FT_NEW_ARRAY( face->metrics, face->nmetrics ) )
return error; return error;
metrics = face->metrics; /* we handle glyph index 0 later on */
metrics = face->metrics + 1;
FT_TRACE4(( "\n" )); FT_TRACE4(( "\n" ));
for ( i = 0; i < nmetrics; i++, metrics++ ) for ( i = 1; i < face->nmetrics; i++, metrics++ )
{ {
FT_TRACE5(( " idx %ld:", i )); FT_TRACE5(( " idx %ld:", i ));
error = pcf_get_metric( stream, format, metrics ); error = pcf_get_metric( stream, format, metrics );
@ -808,12 +814,10 @@ THE SOFTWARE.
pcf_get_bitmaps( FT_Stream stream, pcf_get_bitmaps( FT_Stream stream,
PCF_Face face ) PCF_Face face )
{ {
FT_Error error; FT_Error error;
FT_Memory memory = FT_FACE( face )->memory; FT_ULong bitmapSizes[GLYPHPADOPTIONS];
FT_ULong* offsets = NULL; FT_ULong format, size, pos;
FT_ULong bitmapSizes[GLYPHPADOPTIONS]; FT_ULong nbitmaps, orig_nbitmaps, i, sizebitmaps = 0;
FT_ULong format, size;
FT_ULong nbitmaps, orig_nbitmaps, i, sizebitmaps = 0;
error = pcf_seek_to_table_type( stream, error = pcf_seek_to_table_type( stream,
@ -859,31 +863,46 @@ THE SOFTWARE.
FT_TRACE4(( " number of bitmaps: %ld\n", orig_nbitmaps )); FT_TRACE4(( " number of bitmaps: %ld\n", orig_nbitmaps ));
/* see comment in `pcf_get_metrics' */ /* see comment in `pcf_get_metrics' */
if ( orig_nbitmaps > 65536 ) if ( orig_nbitmaps > 65534 )
{ {
FT_TRACE0(( "pcf_get_bitmaps:" FT_TRACE0(( "pcf_get_bitmaps:"
" only loading first 65536 bitmaps\n" )); " only loading first 65534 bitmaps\n" ));
nbitmaps = 65536; nbitmaps = 65534;
} }
else else
nbitmaps = orig_nbitmaps; nbitmaps = orig_nbitmaps;
if ( nbitmaps != face->nmetrics ) /* no extra bitmap for glyph 0 */
if ( nbitmaps != face->nmetrics - 1 )
return FT_THROW( Invalid_File_Format ); return FT_THROW( Invalid_File_Format );
if ( FT_NEW_ARRAY( offsets, nbitmaps ) ) /* start position of bitmap data */
return error; pos = stream->pos + nbitmaps * 4 + 4 * 4;
FT_TRACE5(( "\n" )); FT_TRACE5(( "\n" ));
for ( i = 0; i < nbitmaps; i++ ) for ( i = 1; i <= nbitmaps; i++ )
{ {
FT_ULong offset;
if ( PCF_BYTE_ORDER( format ) == MSBFirst ) if ( PCF_BYTE_ORDER( format ) == MSBFirst )
(void)FT_READ_ULONG( offsets[i] ); (void)FT_READ_ULONG( offset );
else else
(void)FT_READ_ULONG_LE( offsets[i] ); (void)FT_READ_ULONG_LE( offset );
FT_TRACE5(( " bitmap %lu: offset %lu (0x%lX)\n", FT_TRACE5(( " bitmap %lu: offset %lu (0x%lX)\n",
i, offsets[i], offsets[i] )); i, offset, offset ));
/* right now, we only check the offset with a rough estimate; */
/* actual bitmaps are only loaded on demand */
if ( offset > size )
{
FT_TRACE0(( "pcf_get_bitmaps:"
" invalid offset to bitmap data of glyph %lu\n", i ));
face->metrics[i].bits = pos;
}
else
face->metrics[i].bits = pos + offset;
} }
if ( error ) if ( error )
goto Bail; goto Bail;
@ -910,24 +929,9 @@ THE SOFTWARE.
FT_UNUSED( sizebitmaps ); /* only used for debugging */ FT_UNUSED( sizebitmaps ); /* only used for debugging */
/* right now, we only check the bitmap offsets; */
/* actual bitmaps are only loaded on demand */
for ( i = 0; i < nbitmaps; i++ )
{
/* rough estimate */
if ( offsets[i] > size )
{
FT_TRACE0(( "pcf_get_bitmaps:"
" invalid offset to bitmap data of glyph %lu\n", i ));
}
else
face->metrics[i].bits = stream->pos + offsets[i];
}
face->bitmapsFormat = format; face->bitmapsFormat = format;
Bail: Bail:
FT_FREE( offsets );
return error; return error;
} }
@ -1062,41 +1066,52 @@ THE SOFTWARE.
defaultCharCol = enc->firstCol; defaultCharCol = enc->firstCol;
} }
/* FreeType mandates that glyph index 0 is the `undefined glyph', */ /*
/* which PCF calls the `default character'. For this reason, we */ * FreeType mandates that glyph index 0 is the `undefined glyph', which
/* swap the positions of glyph index 0 and the index corresponding */ * PCF calls the `default character'. However, FreeType needs glyph
/* to `defaultChar' in case they are different. */ * index 0 to be used for the undefined glyph only, which is is not the
* case for PCF. For this reason, we add one slot for glyph index 0 and
/* `stream->cursor' still points at the beginning of the frame; */ * simply copy the default character to it.
/* we can thus easily get the offset to the default character */ *
* `stream->cursor' still points to the beginning of the frame; we can
* thus easily get the offset to the default character.
*/
pos = stream->cursor + pos = stream->cursor +
2 * ( ( defaultCharRow - enc->firstRow ) * 2 * ( ( defaultCharRow - enc->firstRow ) *
( enc->lastCol - enc->firstCol + 1 ) + ( enc->lastCol - enc->firstCol + 1 ) +
defaultCharCol - enc->firstCol ); defaultCharCol - enc->firstCol );
if ( PCF_BYTE_ORDER( format ) == MSBFirst ) if ( PCF_BYTE_ORDER( format ) == MSBFirst )
defaultCharEncodingOffset = FT_PEEK_USHORT( pos ); defaultCharEncodingOffset = FT_PEEK_USHORT( pos );
else else
defaultCharEncodingOffset = FT_PEEK_USHORT_LE( pos ); defaultCharEncodingOffset = FT_PEEK_USHORT_LE( pos );
if ( defaultCharEncodingOffset >= face->nmetrics ) if ( defaultCharEncodingOffset == 0xFFFF )
{ {
FT_TRACE0(( "pcf_get_encodings:" FT_TRACE0(( "pcf_get_encodings:"
" Invalid glyph index for default character," " No glyph for default character,\n"
" setting to zero\n" )); " "
defaultCharEncodingOffset = 0; " setting it to the first glyph of the font\n" ));
defaultCharEncodingOffset = 1;
} }
else
if ( defaultCharEncodingOffset )
{ {
/* do the swapping */ defaultCharEncodingOffset++;
PCF_MetricRec tmp = face->metrics[defaultCharEncodingOffset];
if ( defaultCharEncodingOffset >= face->nmetrics )
face->metrics[defaultCharEncodingOffset] = face->metrics[0]; {
face->metrics[0] = tmp; FT_TRACE0(( "pcf_get_encodings:"
" Invalid glyph index for default character,\n"
" "
" setting it to the first glyph of the font\n" ));
defaultCharEncodingOffset = 1;
}
} }
/* copy metrics of default character to index 0 */
face->metrics[0] = face->metrics[defaultCharEncodingOffset];
/* now loop over all values */
offset = enc->offset; offset = enc->offset;
for ( i = enc->firstRow; i <= enc->lastRow; i++ ) for ( i = enc->firstRow; i <= enc->lastRow; i++ )
{ {
@ -1111,15 +1126,9 @@ THE SOFTWARE.
else else
encodingOffset = FT_GET_USHORT_LE(); encodingOffset = FT_GET_USHORT_LE();
if ( encodingOffset != 0xFFFFU ) /* everything is off by 1 due to the artificial glyph 0 */
{ *offset++ = encodingOffset == 0xFFFF ? 0xFFFF
if ( encodingOffset == defaultCharEncodingOffset ) : encodingOffset + 1;
encodingOffset = 0;
else if ( encodingOffset == 0 )
encodingOffset = defaultCharEncodingOffset;
}
*offset++ = encodingOffset;
} }
} }
FT_Stream_ExitFrame( stream ); FT_Stream_ExitFrame( stream );