Fix for use of non portable strnstr function

Author: doxygen

src/markdown.cpp

@@ -51,6 +51,7 @@
 #include "config.h"
 #include "section.h"
 #include "message.h"
+#include "portable.h"
 
 //-----------
 
@@ -1031,7 +1032,7 @@ static int processCodeSpan(GrowBuf &out, const char *data, int /*offset*/, int s
 
 static void addStrEscapeUtf8Nbsp(GrowBuf &out,const char *s,int len)
 {
-  if (strnstr(s,g_doxy_nsbp,len)==0) // no escape needed -> fast
+  if (Portable::strnstr(s,g_doxy_nsbp,len)==0) // no escape needed -> fast
   {
     out.addStr(s,len);
   }

src/portable.cpp

@@ -475,3 +475,18 @@ void Portable::setShortDir(void)
   delete [] buffer;
 #endif
 }
+
+
+char *Portable::strnstr(const char *haystack, const char *needle, size_t haystack_len)
+{
+  size_t needle_len = strnlen(needle, haystack_len);
+  if (needle_len < haystack_len || !needle[needle_len]) 
+  {
+    char *x = static_cast<char*>(memmem(haystack, haystack_len, needle, needle_len));
+    if (x && !memchr(haystack, 0, x - haystack))
+    {
+      return x;
+    }
+  }
+  return 0;
+}

src/portable.h

@@ -42,6 +42,7 @@ namespace Portable
   bool           isAbsolutePath(const char *fileName);
   void           correct_path(void);
   void           setShortDir(void);
+  char *         strnstr(const char *haystack, const char *needle, size_t haystack_len);
 }