[462781] Allow longer paths on Windows.

Bug: https://bugs.eclipse.org/bugs/show_bug.cgi?id=462781

ChangeLog.txt

@@ -1,3 +1,6 @@
+1.4.1 - 2015xxxx
+================
+
 Broker:
 - Fix possible crash under heavy network load. Closes #463241.
 - Fix possible crash when using pattern ACLs.
@@ -12,6 +15,7 @@ Client library:
 - Return -1 on error from mosquitto_socket(). Closes #461705.
 - Fix crash on multiple calls to mosquitto_lib_init/mosquitto_lib_cleanup.
   Closes #462780.
+- Allow longer paths on Windows. Closes #462781.
 
 
 1.4 - 20150218

lib/util_mosq.c

@@ -307,10 +307,10 @@ int _mosquitto_hex2bin(const char *hex, unsigned char *bin, int bin_max_len)
 FILE *_mosquitto_fopen(const char *path, const char *mode)
 {
 #ifdef WIN32
-	char buf[MAX_PATH];
+	char buf[4096];
 	int rc;
-	rc = ExpandEnvironmentStrings(path, buf, MAX_PATH);
-	if(rc == 0 || rc == MAX_PATH){
+	rc = ExpandEnvironmentStrings(path, buf, 4096);
+	if(rc == 0 || rc > 4096){
 		return NULL;
 	}else{
 		return fopen(buf, mode);