Return an error on increment/decrement larger than 32-bit unsigned

While the memcached protocol allows for 64-bit increments or decrements,
the libmemcached API is limited to a 32-bit adjustment value.

Protocol: https://github.com/memcached/memcached/blob/master/doc/protocol.txt#L274
API: http://docs.libmemcached.org/memcached_auto.html

Author: sodabrew

php_memcached.c

@@ -2185,7 +2185,8 @@ static void php_memc_deleteMulti_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by
 static void php_memc_incdec_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key, zend_bool incr)
 {
 	zend_string *key, *server_key = NULL;
-	long  offset = 1;
+	zend_long offset = 1;
+	uint32_t offset32 = 0;
 	uint64_t value = UINT64_MAX, initial = 0;
 	time_t expiry = 0;
 	memcached_return status;
@@ -2208,7 +2209,12 @@ static void php_memc_incdec_impl(INTERNAL_FUNCTION_PARAMETERS, zend_bool by_key,
 	MEMC_CHECK_KEY(intern, key);
 
 	if (offset < 0) {
-		php_error_docref(NULL, E_WARNING, "offset has to be > 0");
+		php_error_docref(NULL, E_WARNING, "offset cannot be a negative value");
+		RETURN_FALSE;
+	}
+
+	if (offset > UINT_MAX) {
+		php_error_docref(NULL, E_WARNING, "offset cannot be larger than %d", UINT_MAX);
 		RETURN_FALSE;
 	}
 

tests/incrdecr.phpt

@@ -36,6 +36,12 @@ var_dump($m->get('foo'));
 $m->decrement('foo', -1);
 echo $php_errormsg, "\n";
 var_dump($m->get('foo'));
+$m->increment('foo', 4294967295);
+echo $php_errormsg, "\n";
+var_dump($m->get('foo'));
+$m->decrement('foo', 4294967295);
+echo $php_errormsg, "\n";
+var_dump($m->get('foo'));
 
 --EXPECT--
 Not there
@@ -52,7 +58,9 @@ int(4)
 int(3)
 int(1)
 Invalid offset
-Memcached::increment(): offset has to be > 0
+Memcached::increment(): offset cannot be negative
+int(1)
+Memcached::decrement(): offset cannot be negative
 int(1)
-Memcached::decrement(): offset has to be > 0
+Memcached::decrement(): offset cannot be larger than 2147483647
 int(1)

tests/incrdecr_bykey.phpt

@@ -46,7 +46,7 @@ int(4)
 int(3)
 int(1)
 Invalid offset
-Memcached::incrementByKey(): offset has to be > 0
+Memcached::incrementByKey(): offset cannot be negative
 int(1)
-Memcached::decrementByKey(): offset has to be > 0
+Memcached::decrementByKey(): offset cannot be negative
 int(1)