[cache] Fix a possible overflow by signed integer comparison.
Improve the code by 5d3ff05615dda6d1325ed612381a17a0df04c975 ,
issues are found by Behdad Esfahbod and Werner Lemberg.
* src/cache/ftcbasic.c (FTC_ImageCache_Lookup): Replace
a subtraction to check higher bit by a bit operation,
and cpp-conditionalize for appropriate systems. Add better
documentation to the comment.
(FTC_ImageCache_LookupScaler): Ditto.
(FTC_SBitCache_Lookup): Ditto.
(FTC_SBitCache_LookupScaler): Ditto.
diff --git a/ChangeLog b/ChangeLog
index b25a822..62618f8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2017-09-13 suzuki toshiya <mpsuzuki@hiroshima-u.ac.jp>
+
+ [cache] Fix a possible overflow by signed integer comparison.
+
+ Improve the code by 5d3ff05615dda6d1325ed612381a17a0df04c975 ,
+ issues are found by Behdad Esfahbod and Werner Lemberg.
+
+ * src/cache/ftcbasic.c (FTC_ImageCache_Lookup): Replace
+ a subtraction to check higher bit by a bit operation,
+ and cpp-conditionalize for appropriate systems. Add better
+ documentation to the comment.
+ (FTC_ImageCache_LookupScaler): Ditto.
+ (FTC_SBitCache_Lookup): Ditto.
+ (FTC_SBitCache_LookupScaler): Ditto.
+
2017-09-13 Werner Lemberg <wl@gnu.org>
[autofit] Really fix #41334 (#52000).
diff --git a/src/cache/ftcbasic.c b/src/cache/ftcbasic.c
index 289bd5c..59221f2 100644
--- a/src/cache/ftcbasic.c
+++ b/src/cache/ftcbasic.c
@@ -304,10 +304,19 @@
if ( anode )
*anode = NULL;
- if ( (FT_ULong)( type->flags - FT_INT_MIN ) > FT_UINT_MAX )
+/*
+ * internal FTC_BasicAttr->load_flags is typed FT_UInt,
+ * but public FT_ImageType->flags is typed FT_Int32
+ *
+ * On 16bit systems, higher bits of type->flags
+ * could not be handled.
+ */
+#if 0xFFFFFFFFUL > FT_UINT_MAX
+ if ( (type->flags & (FT_ULong)FT_UINT_MAX) )
FT_TRACE1(( "FTC_ImageCache_Lookup:"
" higher bits in load_flags 0x%x are dropped\n",
(FT_ULong)type->flags & ~((FT_ULong)FT_UINT_MAX) ));
+#endif
query.attrs.scaler.face_id = type->face_id;
query.attrs.scaler.width = type->width;
@@ -377,11 +386,19 @@
if ( anode )
*anode = NULL;
- /* `FT_Load_Glyph' and `FT_Load_Char' take FT_UInt flags */
+/*
+ * internal FTC_BasicAttr->load_flags is typed FT_UInt,
+ * but public FT_Face->face_flags is typed FT_Long.
+ *
+ * On long > int systems, higher bits of load_flags
+ * could not be handled.
+ */
+#if FT_ULONG_MAX > FT_UINT_MAX
if ( load_flags > FT_UINT_MAX )
FT_TRACE1(( "FTC_ImageCache_LookupScaler:"
" higher bits in load_flags 0x%x are dropped\n",
load_flags & ~((FT_ULong)FT_UINT_MAX) ));
+#endif
query.attrs.scaler = scaler[0];
query.attrs.load_flags = (FT_UInt)load_flags;
@@ -487,10 +504,19 @@
*ansbit = NULL;
- if ( (FT_ULong)( type->flags - FT_INT_MIN ) > FT_UINT_MAX )
+/*
+ * internal FTC_BasicAttr->load_flags is typed FT_UInt,
+ * but public FT_ImageType->flags is typed FT_Int32
+ *
+ * On 16bit systems, higher bits of type->flags
+ * could not be handled.
+ */
+#if 0xFFFFFFFFUL > FT_UINT_MAX
+ if ( (type->flags & (FT_ULong)FT_UINT_MAX) )
FT_TRACE1(( "FTC_ImageCache_Lookup:"
" higher bits in load_flags 0x%x are dropped\n",
(FT_ULong)type->flags & ~((FT_ULong)FT_UINT_MAX) ));
+#endif
query.attrs.scaler.face_id = type->face_id;
query.attrs.scaler.width = type->width;
@@ -562,11 +588,19 @@
*ansbit = NULL;
- /* `FT_Load_Glyph' and `FT_Load_Char' take FT_UInt flags */
+/*
+ * internal FTC_BasicAttr->load_flags is typed FT_UInt,
+ * but public FT_Face->face_flags is typed FT_Long.
+ *
+ * On long > int systems, higher bits of load_flags
+ * could not be handled.
+ */
+#if FT_ULONG_MAX > FT_UINT_MAX
if ( load_flags > FT_UINT_MAX )
FT_TRACE1(( "FTC_ImageCache_LookupScaler:"
" higher bits in load_flags 0x%x are dropped\n",
load_flags & ~((FT_ULong)FT_UINT_MAX) ));
+#endif
query.attrs.scaler = scaler[0];
query.attrs.load_flags = (FT_UInt)load_flags;
