Patch to add strchrnul to RarVM

diff --git a/Makefile b/Makefile
index f0fa37a..dd22b84 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,4 @@
+# Add -DNEEDS_STRCHRNUL to end of CFLAGS if necessary
 CFLAGS = -ggdb3 -O0 -march=native -std=gnu99 -Wall
 LDFLAGS    = $(CFLAGS) -lz
 RARAS  = ./raras
@@ -14,7 +15,7 @@ RARLD = ./rarld

 all:   raras rarld sample.rar test
 rarld: rarld.o bitbuffer.o
-raras: parser.o raras.o bitbuffer.o
+raras: strchrnul.o parser.o raras.o bitbuffer.o
 bitbuffer_test: bitbuffer_test.o bitbuffer.o

 test: bitbuffer_test
diff --git a/raras.c b/raras.c
index 5ee96ea..e4be757 100644
--- a/raras.c
+++ b/raras.c
@@ -22,6 +22,8 @@
 #include "bitbuffer.h"
 #include "rar.h"

+#include "strchrnul.h"
+
 int main(int argc, char **argv)
 {
     FILE     *input       = NULL;
diff --git a/strchrnul.c b/strchrnul.c
new file mode 100644
index 0000000..a3fec5e
--- /dev/null
+++ b/strchrnul.c
@@ -0,0 +1,14 @@
+#include <string.h>
+#include "strchrnul.h"
+
+char *strchrnul(const char *s, int c)
+{
+   char *ptr = strchr(s, c);
+
+   if (!ptr)
+   {
+       ptr = strchr(s, '\0');
+   }
+
+   return ptr;
+}
\ No newline at end of file
diff --git a/strchrnul.h b/strchrnul.h
new file mode 100644
index 0000000..b7fb1bb
--- /dev/null
+++ b/strchrnul.h
@@ -0,0 +1,8 @@
+#ifndef __STRCHRNUL_H
+#define __STRCHRNUL_H
+
+#ifdef NEEDS_STRCHRNUL
+   char *strchrnul(const char *s, int c);
+#endif
+
+#endif
\ No newline at end of file