[freetype2] master c5a2254: ftcalc.h: Avoid left-shift of negative numbers.

[Werner LEMBERG]

branch: master
commit c5a225413ffd6f3e032cede5a14d64a2c2c047a2
Author: Werner Lemberg <address@hidden>
Commit: Werner Lemberg <address@hidden>

    ftcalc.h: Avoid left-shift of negative numbers.
    
    Reported as
    
      https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2055
    
    * include/freetype/internal/ftcalc.h (INT_TO_F26DOT6,
    INT_TO_F2DOT14, INT_TO_FIXED, F2DOT14_TO_FIXED): Use multiplication.
---
 ChangeLog                          | 11 +++++++++++
 include/freetype/internal/ftcalc.h |  8 ++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 77446ec..5976f0e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2017-06-03  Werner Lemberg  <address@hidden>
+
+       ftcalc.h: Avoid left-shift of negative numbers.
+
+       Reported as
+
+         https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=2055
+
+       * include/freetype/internal/ftcalc.h (INT_TO_F26DOT6,
+       INT_TO_F2DOT14, INT_TO_FIXED, F2DOT14_TO_FIXED): Use multiplication.
+
 2017-06-02  Werner Lemberg  <address@hidden>
 
        [cff] Even more integer overflows.
diff --git a/include/freetype/internal/ftcalc.h 
b/include/freetype/internal/ftcalc.h
index 2b040fe..5902e19 100644
--- a/include/freetype/internal/ftcalc.h
+++ b/include/freetype/internal/ftcalc.h
@@ -399,10 +399,10 @@ FT_BEGIN_HEADER
 #endif /* 0 */
 
 
-#define INT_TO_F26DOT6( x )    ( (FT_Long)(x) << 6  )
-#define INT_TO_F2DOT14( x )    ( (FT_Long)(x) << 14 )
-#define INT_TO_FIXED( x )      ( (FT_Long)(x) << 16 )
-#define F2DOT14_TO_FIXED( x )  ( (FT_Long)(x) << 2  )
+#define INT_TO_F26DOT6( x )    ( (FT_Long)(x) * 64  )    /* << 6  */
+#define INT_TO_F2DOT14( x )    ( (FT_Long)(x) * 16384 )  /* << 14 */
+#define INT_TO_FIXED( x )      ( (FT_Long)(x) * 65536 )  /* << 16 */
+#define F2DOT14_TO_FIXED( x )  ( (FT_Long)(x) * 4 )      /* << 2  */
 #define FIXED_TO_INT( x )      ( FT_RoundFix( x ) >> 16 )
 
 #define ROUND_F26DOT6( x )     ( x >= 0 ? (    ( (x) + 32 ) & -64 )     \