Fix ISANYOF encountering a zero byte in the input.

mity · mity · commit 22ca89a30089 · 2020-09-29T21:33:43.000+02:00
When it happened, it could lead to unexpected results, including broken internal state of the parser. Fixes #130.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,16 @@
 # MD4C Change Log
 
 
+## Next Version (Work in Progress)
+
+Fixes:
+
+* [#130](https://github.com/mity/md4c/issues/130):
+  Fix `ISANYOF` macro, which could provide unexpected results when encountering
+  zero byte in the input text; in some cases leading to broken internal state
+  of the parser.
+
+
 ## Version 0.4.5
 
 Fixes:
diff --git a/src/md4c.c b/src/md4c.c
@@ -276,7 +276,7 @@ struct MD_VERBATIMLINE_tag {
 /* Character classification.
  * Note we assume ASCII compatibility of code points < 128 here. */
 #define ISIN_(ch, ch_min, ch_max)       ((ch_min) <= (unsigned)(ch) && (unsigned)(ch) <= (ch_max))
-#define ISANYOF_(ch, palette)           (md_strchr((palette), (ch)) != NULL)
+#define ISANYOF_(ch, palette)           ((ch) != _T('\0')  &&  md_strchr((palette), (ch)) != NULL)
 #define ISANYOF2_(ch, ch1, ch2)         ((ch) == (ch1) || (ch) == (ch2))
 #define ISANYOF3_(ch, ch1, ch2, ch3)    ((ch) == (ch1) || (ch) == (ch2) || (ch) == (ch3))
 #define ISASCII_(ch)                    ((unsigned)(ch) <= 127)
