commit baf7779d2d6e4810168a8f036bbf8f9e6493dd1a
author Behdad Esfahbod <behdad@behdad.org> Tue Nov 14 21:53:48 2017 -0800
committer Behdad Esfahbod <behdad@behdad.org> Tue Nov 14 21:55:37 2017 -0800
tree 2435fd01ff34f8c120116755e933798c0e99a038
parent 173dab6300d9b492f2d1c68f9e8f7817211a3462

Limit how much recursion GSUB/GPOS does

This only counts recursions right now.  Good start.

Hopefully...
Fixes https://github.com/behdad/harfbuzz/issues/429

src/hb-buffer-private.hh

diff --git a/src/hb-buffer-private.hh b/src/hb-buffer-private.hh
index c694cd9..97bdc1b 100644
--- a/src/hb-buffer-private.hh
+++ b/src/hb-buffer-private.hh
@@ -35,8 +35,8 @@
 #include "hb-unicode-private.hh"
 
 
-#ifndef HB_BUFFER_MAX_EXPANSION_FACTOR
-#define HB_BUFFER_MAX_EXPANSION_FACTOR 32
+#ifndef HB_BUFFER_MAX_LEN_FACTOR
+#define HB_BUFFER_MAX_LEN_FACTOR 32
 #endif
 #ifndef HB_BUFFER_MAX_LEN_MIN
 #define HB_BUFFER_MAX_LEN_MIN 8192
@@ -45,6 +45,16 @@
 #define HB_BUFFER_MAX_LEN_DEFAULT 0x3FFFFFFF /* Shaping more than a billion chars? Let us know! */
 #endif
 
+#ifndef HB_BUFFER_MAX_OPS_FACTOR
+#define HB_BUFFER_MAX_OPS_FACTOR 64
+#endif
+#ifndef HB_BUFFER_MAX_OPS_MIN
+#define HB_BUFFER_MAX_OPS_MIN 1024
+#endif
+#ifndef HB_BUFFER_MAX_OPS_DEFAULT
+#define HB_BUFFER_MAX_OPS_DEFAULT 0x1FFFFFFF /* Shaping more than a billion operations? Let us know! */
+#endif
+
 static_assert ((sizeof (hb_glyph_info_t) == 20), "");
 static_assert ((sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t)), "");
 
@@ -84,6 +94,7 @@
   hb_codepoint_t replacement; /* U+FFFD or something else. */
   hb_buffer_scratch_flags_t scratch_flags; /* Have space-flallback, etc. */
   unsigned int max_len; /* Maximum allowed len. */
+  int max_ops; /* Maximum allowed operations. */
 
   /* Buffer contents */
   hb_buffer_content_type_t content_type;