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* src/cff/cffgload.c (cff_decoder_parse_charstrings): No longer 

assume that the first argument on the stack is the bottom-most
element.  Two reasons:

  o According to people from Adobe it is missing in the Type 2
    specification that pushing of additional, superfluous arguments
    on the stack is prohibited.

  o Acroread in general handles fonts differently, namely by popping
    the number of arguments needed for a particular operand (as a PS
    interpreter would do).  In case of buggy fonts this causes a
    different interpretation which of the elements on the stack are
    superfluous and which not.

Since there are CFF subfonts (embedded in PDFs) which rely on
Acroread's behaviour, FreeType now does the same.
This commit is contained in:
Werner Lemberg 2008-07-30 05:28:37 +00:00
parent 830846e645
commit 806f59341d
2 changed files with 216 additions and 135 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
ChangeLog
View File

@ -1,3 +1,22 @@
2008-07-30 Werner Lemberg <wl@gnu.org>
* src/cff/cffgload.c (cff_decoder_parse_charstrings): No longer
assume that the first argument on the stack is the bottom-most
element. Two reasons:
o According to people from Adobe it is missing in the Type 2
specification that pushing of additional, superfluous arguments
on the stack is prohibited.
o Acroread in general handles fonts differently, namely by popping
the number of arguments needed for a particular operand (as a PS
interpreter would do). In case of buggy fonts this causes a
different interpretation which of the elements on the stack are
superfluous and which not.
Since there are CFF subfonts (embedded in PDFs) which rely on
Acroread's behaviour, FreeType now does the same.
2008-07-27 Werner Lemberg <wl@gnu.org>
Add extra mappings for `Tcommaaccent' and `tcommaaccent'. This

332
src/cff/cffgload.c
View File

@ -123,6 +123,11 @@
#define CFF_COUNT_EXACT 0x40
#define CFF_COUNT_CLEAR_STACK 0x20
/* count values which have the `CFF_COUNT_CHECK_WIDTH' flag set are */
/* used for checking the width and requested numbers of arguments */
/* only; they are set to zero afterwards */
/* the other two flags are informative only and unused currently */
static const FT_Byte cff_argument_counts[] =
{
@ -952,6 +957,11 @@
}
else
{
/* The specification says that normally arguments are to be taken */
/* from the bottom of the stack. However, this seems not to be */
/* correct, at least for Acroread 7.0.8 on GNU/Linux: It pops the */
/* arguments similar to a PS interpreter. */
FT_Fixed* args = decoder->top;
FT_Int num_args = (FT_Int)( args - decoder->stack );
FT_Int req_args;
@ -1138,6 +1148,7 @@
default:
;
}
if ( op == cff_op_unknown )
goto Syntax_Error;
@ -1145,8 +1156,6 @@
req_args = cff_argument_counts[op];
if ( req_args & CFF_COUNT_CHECK_WIDTH )
{
args = stack;
if ( num_args > 0 && decoder->read_width )
{
/* If `nominal_width' is non-zero, the number is really a */
@ -1195,7 +1204,6 @@
/* Consumed an argument. */
num_args--;
args++;
}
}
@ -1209,6 +1217,14 @@
args -= req_args;
num_args -= req_args;
/* At this point, `args' points to the first argument of the */
/* operand in case `req_args' isn't zero. Otherwise, we have */
/* to adjust `args' manually. */
/* Note that we only pop arguments from the stack which we */
/* really need and can digest so that we can continue in case */
/* of superfluous stack elements. */
switch ( op )
{
case cff_op_hstem:
@ -1225,7 +1241,7 @@
hinter->stems( hinter->hints,
( op == cff_op_hstem || op == cff_op_hstemhm ),
num_args / 2,
args );
args - ( num_args & ~1 ) );
decoder->num_hints += num_args / 2;
args = stack;
@ -1245,7 +1261,7 @@
hinter->stems( hinter->hints,
0,
num_args / 2,
args );
args - ( num_args & ~1 ) );
decoder->num_hints += num_args / 2;
}
@ -1290,8 +1306,8 @@
cff_builder_close_contour( builder );
builder->path_begun = 0;
x += args[0];
y += args[1];
x += args[-2];
y += args[-1];
args = stack;
break;
@ -1300,7 +1316,7 @@
cff_builder_close_contour( builder );
builder->path_begun = 0;
y += args[0];
y += args[-1];
args = stack;
break;
@ -1309,7 +1325,7 @@
cff_builder_close_contour( builder );
builder->path_begun = 0;
x += args[0];
x += args[-1];
args = stack;
break;
@ -1320,10 +1336,10 @@
check_points( builder, num_args / 2 ) )
goto Fail;
if ( num_args < 2 || num_args & 1 )
if ( num_args < 2 )
goto Stack_Underflow;
args = stack;
args -= num_args & ~1;
while ( args < decoder->top )
{
x += args[0];
@ -1343,6 +1359,9 @@
FT_TRACE4(( op == cff_op_hlineto ? " hlineto\n"
: " vlineto\n" ));
if ( num_args < 1 )
goto Stack_Underflow;
if ( cff_builder_start_point ( builder, x, y ) ||
check_points( builder, num_args ) )
goto Fail;
@ -1366,105 +1385,137 @@
break;
case cff_op_rrcurveto:
FT_TRACE4(( " rrcurveto\n" ));
/* check number of arguments; must be a multiple of 6 */
if ( num_args % 6 != 0 )
goto Stack_Underflow;
if ( cff_builder_start_point ( builder, x, y ) ||
check_points( builder, num_args / 2 ) )
goto Fail;
args = stack;
while ( args < decoder->top )
{
x += args[0];
y += args[1];
cff_builder_add_point( builder, x, y, 0 );
x += args[2];
y += args[3];
cff_builder_add_point( builder, x, y, 0 );
x += args[4];
y += args[5];
cff_builder_add_point( builder, x, y, 1 );
args += 6;
FT_Int nargs;
FT_TRACE4(( " rrcurveto\n" ));
if ( num_args < 6 )
goto Stack_Underflow;
nargs = num_args - num_args % 6;
if ( cff_builder_start_point ( builder, x, y ) ||
check_points( builder, nargs / 2 ) )
goto Fail;
args -= nargs;
while ( args < decoder->top )
{
x += args[0];
y += args[1];
cff_builder_add_point( builder, x, y, 0 );
x += args[2];
y += args[3];
cff_builder_add_point( builder, x, y, 0 );
x += args[4];
y += args[5];
cff_builder_add_point( builder, x, y, 1 );
args += 6;
}
args = stack;
}
args = stack;
break;
case cff_op_vvcurveto:
FT_TRACE4(( " vvcurveto\n" ));
if ( cff_builder_start_point( builder, x, y ) )
goto Fail;
args = stack;
if ( num_args & 1 )
{
x += args[0];
args++;
num_args--;
FT_Int nargs;
FT_TRACE4(( " vvcurveto\n" ));
if ( num_args < 4 )
goto Stack_Underflow;
/* if num_args isn't of the form 4n or 4n+1, */
/* we reduce it to 4n+1 */
nargs = num_args - num_args % 4;
if ( num_args - nargs > 0 )
nargs += 1;
if ( cff_builder_start_point( builder, x, y ) )
goto Fail;
args -= nargs;
if ( nargs & 1 )
{
x += args[0];
args++;
nargs--;
}
if ( check_points( builder, 3 * ( nargs / 4 ) ) )
goto Fail;
while ( args < decoder->top )
{
y += args[0];
cff_builder_add_point( builder, x, y, 0 );
x += args[1];
y += args[2];
cff_builder_add_point( builder, x, y, 0 );
y += args[3];
cff_builder_add_point( builder, x, y, 1 );
args += 4;
}
args = stack;
}
if ( num_args % 4 != 0 )
goto Stack_Underflow;
if ( check_points( builder, 3 * ( num_args / 4 ) ) )
goto Fail;
while ( args < decoder->top )
{
y += args[0];
cff_builder_add_point( builder, x, y, 0 );
x += args[1];
y += args[2];
cff_builder_add_point( builder, x, y, 0 );
y += args[3];
cff_builder_add_point( builder, x, y, 1 );
args += 4;
}
args = stack;
break;
case cff_op_hhcurveto:
FT_TRACE4(( " hhcurveto\n" ));
if ( cff_builder_start_point( builder, x, y ) )
goto Fail;
args = stack;
if ( num_args & 1 )
{
y += args[0];
args++;
num_args--;
FT_Int nargs;
FT_TRACE4(( " hhcurveto\n" ));
if ( num_args < 4 )
goto Stack_Underflow;
/* if num_args isn't of the form 4n or 4n+1, */
/* we reduce it to 4n+1 */
nargs = num_args - num_args % 4;
if ( num_args - nargs > 0 )
nargs += 1;
if ( cff_builder_start_point( builder, x, y ) )
goto Fail;
args -= nargs;
if ( nargs & 1 )
{
y += args[0];
args++;
nargs--;
}
if ( check_points( builder, 3 * ( nargs / 4 ) ) )
goto Fail;
while ( args < decoder->top )
{
x += args[0];
cff_builder_add_point( builder, x, y, 0 );
x += args[1];
y += args[2];
cff_builder_add_point( builder, x, y, 0 );
x += args[3];
cff_builder_add_point( builder, x, y, 1 );
args += 4;
}
args = stack;
}
if ( num_args % 4 != 0 )
goto Stack_Underflow;
if ( check_points( builder, 3 * ( num_args / 4 ) ) )
goto Fail;
while ( args < decoder->top )
{
x += args[0];
cff_builder_add_point( builder, x, y, 0 );
x += args[1];
y += args[2];
cff_builder_add_point( builder, x, y, 0 );
x += args[3];
cff_builder_add_point( builder, x, y, 1 );
args += 4;
}
args = stack;
break;
case cff_op_vhcurveto:
case cff_op_hvcurveto:
{
FT_Int phase;
FT_Int nargs;
FT_TRACE4(( op == cff_op_vhcurveto ? " vhcurveto\n"
@ -1473,18 +1524,25 @@
if ( cff_builder_start_point( builder, x, y ) )
goto Fail;
args = stack;
if ( num_args < 4 || ( num_args % 4 ) > 1 )
if ( num_args < 4 )
goto Stack_Underflow;
if ( check_points( builder, ( num_args / 4 ) * 3 ) )
/* if num_args isn't of the form 8n, 8n+1, 8n+4, or 8n+5, */
/* we reduce it to the largest one which fits */
nargs = num_args - num_args % 4;
if ( num_args - nargs > 0 )
nargs += 1;
args -= nargs;
if ( check_points( builder, ( nargs / 4 ) * 3 ) )
goto Stack_Underflow;
phase = ( op == cff_op_hvcurveto );
while ( num_args >= 4 )
while ( nargs >= 4 )
{
num_args -= 4;
nargs -= 4;
if ( phase )
{
x += args[0];
@ -1493,7 +1551,7 @@
y += args[2];
cff_builder_add_point( builder, x, y, 0 );
y += args[3];
if ( num_args == 1 )
if ( nargs == 1 )
x += args[4];
cff_builder_add_point( builder, x, y, 1 );
}
@ -1505,7 +1563,7 @@
y += args[2];
cff_builder_add_point( builder, x, y, 0 );
x += args[3];
if ( num_args == 1 )
if ( nargs == 1 )
y += args[4];
cff_builder_add_point( builder, x, y, 1 );
}
@ -1518,19 +1576,23 @@
case cff_op_rlinecurve:
{
FT_Int num_lines = ( num_args - 6 ) / 2;
FT_Int num_lines;
FT_Int nargs;
FT_TRACE4(( " rlinecurve\n" ));
if ( num_args < 8 || ( num_args - 6 ) & 1 )
if ( num_args < 8 )
goto Stack_Underflow;
nargs = num_args & ~1;
num_lines = ( nargs - 6 ) / 2;
if ( cff_builder_start_point( builder, x, y ) ||
check_points( builder, num_lines + 3 ) )
goto Fail;
args = stack;
args -= nargs;
/* first, add the line segments */
while ( num_lines > 0 )
@ -1558,19 +1620,24 @@
case cff_op_rcurveline:
{
FT_Int num_curves = ( num_args - 2 ) / 6;
FT_Int num_curves;
FT_Int nargs;
FT_TRACE4(( " rcurveline\n" ));
if ( num_args < 8 || ( num_args - 2 ) % 6 )
if ( num_args < 8 )
goto Stack_Underflow;
nargs = num_args - 2;
nargs = nargs - nargs % 6 + 2;
num_curves = ( nargs - 2 ) / 6;
if ( cff_builder_start_point ( builder, x, y ) ||
check_points( builder, num_curves*3 + 2 ) )
check_points( builder, num_curves * 3 + 2 ) )
goto Fail;
args = stack;
args -= nargs;
/* first, add the curves */
while ( num_curves > 0 )
@ -1603,16 +1670,14 @@
FT_TRACE4(( " hflex1\n" ));
args = stack;
/* adding five more points; 4 control points, 1 on-curve point */
/* make sure we have enough space for the start point if it */
/* adding five more points: 4 control points, 1 on-curve point */
/* -- make sure we have enough space for the start point if it */
/* needs to be added */
if ( cff_builder_start_point( builder, x, y ) ||
check_points( builder, 6 ) )
goto Fail;
/* Record the starting point's y position for later use */
/* record the starting point's y position for later use */
start_y = y;
/* first control point */
@ -1656,8 +1721,6 @@
FT_TRACE4(( " hflex\n" ));
args = stack;
/* adding six more points; 4 control points, 2 on-curve points */
if ( cff_builder_start_point( builder, x, y ) ||
check_points( builder, 6 ) )
@ -1701,11 +1764,12 @@
case cff_op_flex1:
{
FT_Pos start_x, start_y; /* record start x, y values for */
/* alter use */
FT_Fixed dx = 0, dy = 0; /* used in horizontal/vertical */
/* algorithm below */
FT_Int horizontal, count;
FT_Pos start_x, start_y; /* record start x, y values for */
/* alter use */
FT_Fixed dx = 0, dy = 0; /* used in horizontal/vertical */
/* algorithm below */
FT_Int horizontal, count;
FT_Fixed* temp;
FT_TRACE4(( " flex1\n" ));
@ -1722,21 +1786,20 @@
/* XXX: figure out whether this is supposed to be a horizontal */
/* or vertical flex; the Type 2 specification is vague... */
args = stack;
temp = args;
/* grab up to the last argument */
for ( count = 5; count > 0; count-- )
{
dx += args[0];
dy += args[1];
args += 2;
dx += temp[0];
dy += temp[1];
temp += 2;
}
/* rewind */
args = stack;
if ( dx < 0 ) dx = -dx;
if ( dy < 0 ) dy = -dy;
if ( dx < 0 )
dx = -dx;
if ( dy < 0 )
dy = -dy;
/* strange test, but here it is... */
horizontal = ( dx > dy );
@ -1745,7 +1808,8 @@
{
x += args[0];
y += args[1];
cff_builder_add_point( builder, x, y, (FT_Bool)( count == 3 ) );
cff_builder_add_point( builder, x, y,
(FT_Bool)( count == 3 ) );
args += 2;
}
@ -1778,7 +1842,6 @@
check_points( builder, 6 ) )
goto Fail;
args = stack;
for ( count = 6; count > 0; count-- )
{
x += args[0];
@ -1796,18 +1859,17 @@
FT_TRACE4(( " endchar\n" ));
/* We are going to emulate the seac operator. */
if ( num_args == 4 )
if ( num_args >= 4 )
{
/* Save glyph width so that the subglyphs don't overwrite it. */
FT_Pos glyph_width = decoder->glyph_width;
error = cff_operator_seac( decoder,
args[0],
args[1],
(FT_Int)( args[2] >> 16 ),
(FT_Int)( args[3] >> 16 ) );
args += 4;
args[-4],
args[-3],
(FT_Int)( args[-2] >> 16 ),
(FT_Int)( args[-1] >> 16 ) );
decoder->glyph_width = glyph_width;
}