commit 766b2c19e247cfa8006aa2be2e0aeab28b295123
author Alexei Podtelezhnikov <apodtele@gmail.com> Fri Sep 24 22:14:22 2021 -0400
committer Alexei Podtelezhnikov <apodtele@gmail.com> Fri Sep 24 22:14:22 2021 -0400
tree e90b2f1e7f729bf538f19a71f3b57d9bba6150db
parent a69320a9b27ed87f87d2d28fffa04907c4752873

Propagate sign when reading OFF3.

Signed 24-bit values are extremely rare.  FreeType only reads them in
PFR fonts with bitmap strikes conditionally. They have not been seen
in the known fonts.  That is why this bug could never be discovered.
`FT_FRAME_OFF3` propagates sign correctly.

* include/freetype/internal/ftstream.h (FT_PEEK_OFF3, FT_PEEK_OFF3_LE):
Propagate sign into 32-bit value.
(FT_GET_OFF3, FT_READ_OFF3): Needed fixing but removed as unused.

include/freetype/internal/ftstream.h

diff --git a/include/freetype/internal/ftstream.h b/include/freetype/internal/ftstream.h
index 72dd585..7f3af12 100644
--- a/include/freetype/internal/ftstream.h
+++ b/include/freetype/internal/ftstream.h
@@ -196,9 +196,9 @@
                                        FT_BYTE_U32( p, 2,  8 ) | \
                                        FT_BYTE_U32( p, 3,  0 ) )
 
-#define FT_PEEK_OFF3( p )  FT_INT32( FT_BYTE_U32( p, 0, 16 ) | \
-                                     FT_BYTE_U32( p, 1,  8 ) | \
-                                     FT_BYTE_U32( p, 2,  0 ) )
+#define FT_PEEK_OFF3( p )  ( FT_INT32( FT_BYTE_U32( p, 0, 24 ) | \
+                                       FT_BYTE_U32( p, 1, 16 ) | \
+                                       FT_BYTE_U32( p, 2,  8 ) ) >> 8 )
 
 #define FT_PEEK_UOFF3( p )  FT_UINT32( FT_BYTE_U32( p, 0, 16 ) | \
                                        FT_BYTE_U32( p, 1,  8 ) | \
@@ -220,9 +220,9 @@
                                           FT_BYTE_U32( p, 1,  8 ) | \
                                           FT_BYTE_U32( p, 0,  0 ) )
 
-#define FT_PEEK_OFF3_LE( p )  FT_INT32( FT_BYTE_U32( p, 2, 16 ) | \
-                                        FT_BYTE_U32( p, 1,  8 ) | \
-                                        FT_BYTE_U32( p, 0,  0 ) )
+#define FT_PEEK_OFF3_LE( p )  ( FT_INT32( FT_BYTE_U32( p, 2, 24 ) | \
+                                          FT_BYTE_U32( p, 1, 16 ) | \
+                                          FT_BYTE_U32( p, 0,  8 ) ) >> 8 )
 
 #define FT_PEEK_UOFF3_LE( p )  FT_UINT32( FT_BYTE_U32( p, 2, 16 ) | \
                                           FT_BYTE_U32( p, 1,  8 ) | \
@@ -309,7 +309,6 @@
 #define FT_GET_BYTE()       FT_GET_MACRO( FT_Stream_GetByte, FT_Byte )
 #define FT_GET_SHORT()      FT_GET_MACRO( FT_Stream_GetUShort, FT_Short )
 #define FT_GET_USHORT()     FT_GET_MACRO( FT_Stream_GetUShort, FT_UShort )
-#define FT_GET_OFF3()       FT_GET_MACRO( FT_Stream_GetUOffset, FT_Long )
 #define FT_GET_UOFF3()      FT_GET_MACRO( FT_Stream_GetUOffset, FT_ULong )
 #define FT_GET_LONG()       FT_GET_MACRO( FT_Stream_GetULong, FT_Long )
 #define FT_GET_ULONG()      FT_GET_MACRO( FT_Stream_GetULong, FT_ULong )
@@ -337,7 +336,6 @@
 #define FT_READ_CHAR( var )       FT_READ_MACRO( FT_Stream_ReadByte, FT_Char, var )
 #define FT_READ_SHORT( var )      FT_READ_MACRO( FT_Stream_ReadUShort, FT_Short, var )
 #define FT_READ_USHORT( var )     FT_READ_MACRO( FT_Stream_ReadUShort, FT_UShort, var )
-#define FT_READ_OFF3( var )       FT_READ_MACRO( FT_Stream_ReadUOffset, FT_Long, var )
 #define FT_READ_UOFF3( var )      FT_READ_MACRO( FT_Stream_ReadUOffset, FT_ULong, var )
 #define FT_READ_LONG( var )       FT_READ_MACRO( FT_Stream_ReadULong, FT_Long, var )
 #define FT_READ_ULONG( var )      FT_READ_MACRO( FT_Stream_ReadULong, FT_ULong, var )