ref: 8e82a961e7f5c9c7e91022e3ed45d1e56429ef2a
parent: fdcbaf19fef106522eb5a5e11acbd04a3fa6330f
author: Werner Lemberg <[email protected]>
date: Sun Oct 21 07:02:50 EDT 2012
[psaux] Improve parsing of invalid numbers. * src/psaux/psconv.c (PS_Conv_Strtol): Always parse complete number, even in case of overflow. (PS_Conv_ToInt): Only increase cursor if parsing was successful. (PS_Conv_ToFixed): Ditto. Trace underflow and data error.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
2012-10-21 Werner Lemberg <[email protected]>
+ [psaux] Improve parsing of invalid numbers.
+
+ * src/psaux/psconv.c (PS_Conv_Strtol): Always parse complete number,
+ even in case of overflow.
+ (PS_Conv_ToInt): Only increase cursor if parsing was successful.
+ (PS_Conv_ToFixed): Ditto.
+ Trace underflow and data error.
+
+2012-10-21 Werner Lemberg <[email protected]>
+
[smooth] Improve tracing.
* src/smooth/ftgrays.c (gray_sweep): Trace last sweep line of
--- a/src/psaux/psconv.c
+++ b/src/psaux/psconv.c
@@ -86,9 +86,11 @@
FT_Long base )
{FT_Byte* p = *cursor;
- FT_Long num = 0;
- FT_Bool sign = 0;
+ FT_Long num = 0;
+ FT_Bool sign = 0;
+ FT_Bool have_overflow = 0;
+
FT_Long num_limit;
FT_Char c_limit;
@@ -128,27 +130,27 @@
break;
if ( num > num_limit || ( num == num_limit && c > c_limit ) )
- goto Overflow;
- num = num * base + c;
+ have_overflow = 1;
+ else
+ num = num * base + c;
}
*cursor = p;
- Exit:
+ if ( have_overflow )
+ {+ num = 0x7FFFFFFFL;
+ FT_TRACE4(( "!!!OVERFLOW:!!!" ));
+ }
+
if ( sign )
num = -num;
return num;
- Overflow:
- num = 0x7FFFFFFFL;
- FT_TRACE4(( "!!!OVERFLOW:!!!" ));
- goto Exit;
-
Bad:
- num = 0;
FT_TRACE4(( "!!!END OF DATA:!!!" ));
- goto Exit;
+ return 0;
}
@@ -157,21 +159,32 @@
FT_Byte* limit )
{- FT_Byte* p;
+ FT_Byte* p = *cursor;
+ FT_Byte* curp;
+
FT_Long num;
- num = PS_Conv_Strtol( cursor, limit, 10 );
- p = *cursor;
+ curp = p;
+ num = PS_Conv_Strtol( &p, limit, 10 );
+ if ( p == curp )
+ return 0;
+
if ( p < limit && *p == '#' )
{- *cursor = p + 1;
+ p++;
- return PS_Conv_Strtol( cursor, limit, num );
+ curp = p;
+ num = PS_Conv_Strtol( &p, limit, num );
+
+ if ( p == curp )
+ return 0;
}
- else
- return num;
+
+ *cursor = p;
+
+ return num;
}
@@ -181,13 +194,19 @@
FT_Long power_ten )
{FT_Byte* p = *cursor;
- FT_Fixed integral;
- FT_Long decimal = 0, divider = 1;
- FT_Bool sign = 0;
+ FT_Byte* curp;
+ FT_Fixed integral = 0;
+ FT_Long decimal = 0;
+ FT_Long divider = 1;
+ FT_Bool sign = 0;
+ FT_Bool have_overflow = 0;
+ FT_Bool have_underflow = 0;
+
+
if ( p >= limit )
- return 0;
+ goto Bad;
if ( *p == '-' || *p == '+' )
{@@ -195,20 +214,23 @@
p++;
if ( p == limit )
- return 0;
+ goto Bad;
}
+ /* read the integer part */
if ( *p != '.' )
{+ curp = p;
integral = PS_Conv_ToInt( &p, limit );
- if ( integral > 0x7FFF )
- return sign ? -0x7FFFFFFFL : 0x7FFFFFFFL;
+ if ( p == curp )
+ return 0;
- integral <<= 16;
+ if ( integral > 0x7FFF )
+ have_overflow = 1;
+ else
+ integral <<= 16;
}
- else
- integral = 0;
/* read the decimal part */
if ( p < limit && *p == '.' )
@@ -228,18 +250,14 @@
if ( c < 0 || c >= 10 )
break;
- if ( !integral && power_ten > 0 )
+ if ( decimal < 0xCCCCCCCL )
{- power_ten--;
decimal = decimal * 10 + c;
- }
- else
- {- if ( divider < 10000000L )
- {- decimal = decimal * 10 + c;
+
+ if ( !integral && power_ten > 0 )
+ power_ten--;
+ else
divider *= 10;
- }
}
}
}
@@ -247,16 +265,51 @@
/* read exponent, if any */
if ( p + 1 < limit && ( *p == 'e' || *p == 'E' ) )
{+ FT_Long exponent;
+
+
p++;
- power_ten += PS_Conv_ToInt( &p, limit );
+
+ curp = p;
+ exponent = PS_Conv_ToInt( &p, limit );
+
+ if ( curp == p )
+ return 0;
+
+ /* arbitrarily limit exponent */
+ if ( exponent > 1000 )
+ have_overflow = 1;
+ else if ( exponent < -1000 )
+ have_underflow = 1;
+ else
+ power_ten += exponent;
}
+ *cursor = p;
+
+ if ( !integral && !decimal )
+ return 0;
+
+ if ( have_overflow )
+ goto Overflow;
+ if ( have_underflow )
+ goto Underflow;
+
while ( power_ten > 0 )
{if ( integral >= 0xCCCCCCCL )
- return sign ? -0x7FFFFFFFL : 0x7FFFFFFFL;
+ goto Overflow;
integral *= 10;
- decimal *= 10;
+
+ if ( decimal >= 0xCCCCCCCL )
+ {+ if ( divider == 1 )
+ goto Overflow;
+ divider /= 10;
+ }
+ else
+ decimal *= 10;
+
power_ten--;
}
@@ -263,7 +316,14 @@
while ( power_ten < 0 )
{integral /= 10;
- divider *= 10;
+ if ( divider < 0xCCCCCCCL )
+ divider *= 10;
+ else
+ decimal /= 10;
+
+ if ( !integral && !decimal )
+ goto Underflow;
+
power_ten++;
}
@@ -270,17 +330,29 @@
if ( decimal )
{decimal = FT_DivFix( decimal, divider );
- if ( 0x7FFFFFFFL - decimal < integral )
- return sign ? -0x7FFFFFFFL : 0x7FFFFFFFL;
+ /* it's not necessary to check this addition for overflow */
+ /* due to the structure of the real number representation */
integral += decimal;
}
+ Exit:
if ( sign )
integral = -integral;
- *cursor = p;
-
return integral;
+
+ Bad:
+ FT_TRACE4(( "!!!END OF DATA:!!!" ));
+ return 0;
+
+ Overflow:
+ integral = 0x7FFFFFFFL;
+ FT_TRACE4(( "!!!OVERFLOW:!!!" ));
+ goto Exit;
+
+ Underflow:
+ FT_TRACE4(( "!!!UNDERFLOW:!!!" ));
+ return 0;
}