Fix #1237, avoid calling memchr() with unknown size buffer

ut_assert/inc/utassert.h

@@ -44,6 +44,18 @@
 #include <stdio.h>
 #include <math.h>
 
+/**
+ * @brief Flag for use with UtAssert_STRINGBUF_EQ when the string is known to be NULL terminated
+ *
+ * The UtAssert_STRINGBUF_EQ is provided to facilitate checking fixed-length strings, which do not
+ * require NULL termination.
+ *
+ * If this macro is used to compare against a standard C string that is guaranteed to be NULL
+ * terminated, this constant may be passed to the UtAssert_STRINGBUF_EQ macro in place of the
+ * size parameter for that string.
+ */
+#define UTASSERT_STRINGBUF_NULL_TERM SIZE_MAX
+
 /**
  * Define various types of messages that can be generated by a test.
  *
@@ -607,7 +619,9 @@ typedef struct
  *        includes the actual string in the log, but filters embedded newlines to keep the log clean.
  *
  *        If the string arguments are guaranteed to be NULL terminated and/or the max size is
- *        not known, then the SIZE_MAX constant may be passed for the respective string.
+ *        not known, then the UTASSERT_STRINGBUF_NULL_TERM constant may be passed as the size for
+ *        that string.  This mechanism allows this check to be used with normal, terminated C strings,
+ *        as well as fixed-length, unterminated strings.
  *
  */
 #define UtAssert_STRINGBUF_EQ(str1, size1, str2, size2) \

ut_assert/src/utassert.c

@@ -473,6 +473,16 @@ bool UtAssert_StringBufCompare(const char *String1, size_t String1Max, const cha
     {
         EndPtr1 = NULL;
     }
+    else if (String1Max == UTASSERT_STRINGBUF_NULL_TERM)
+    {
+        /*
+         * NOTE: it is technically undefined behavior to pass a size to memchr()
+         * that is larger than the actual buffer, even if it is known/guaranteed
+         * to find a match within the actual buffer.  Therefore the regular strlen()
+         * is used instead.
+         */
+        EndPtr1 = String1 + strlen(String1);
+    }
     else
     {
         EndPtr1 = memchr(String1, 0, String1Max);
@@ -491,6 +501,10 @@ bool UtAssert_StringBufCompare(const char *String1, size_t String1Max, const cha
     {
         EndPtr2 = NULL;
     }
+    else if (String2Max == UTASSERT_STRINGBUF_NULL_TERM)
+    {
+        EndPtr2 = String2 + strlen(String2);
+    }
     else
     {
         EndPtr2 = memchr(String2, 0, String2Max);