Removed assumption that \\ will be present

The function zend_add_ns_func_name_literal is called if the parser finds a function that is not in the global or current namespace. It assumes such a function will have a \\ in it, which is no longer true with the use function patch. The code change above removes that assumption and makes the test work:
PASS use and use function with the same alias [Zend/tests/use_function/conflicting_use_alias.phpt]

Author: Danack

Zend/zend_compile.c

@@ -426,12 +426,16 @@ int zend_add_ns_func_name_literal(zend_op_array *op_array, const zval *zv TSRMLS
 	lc_literal = zend_add_literal(CG(active_op_array), &c TSRMLS_CC);
 	CALCULATE_LITERAL_HASH(lc_literal);
 
-	ns_separator = (const char*)zend_memrchr(Z_STRVAL_P(zv), '\\', Z_STRLEN_P(zv)) + 1;
-	lc_len = Z_STRLEN_P(zv) - (ns_separator - Z_STRVAL_P(zv));
-	lc_name = zend_str_tolower_dup(ns_separator, lc_len);
-	ZVAL_STRINGL(&c, lc_name, lc_len, 0);
-	lc_literal = zend_add_literal(CG(active_op_array), &c TSRMLS_CC);
-	CALCULATE_LITERAL_HASH(lc_literal);
+	ns_separator = (const char*)zend_memrchr(Z_STRVAL_P(zv), '\\', Z_STRLEN_P(zv));
+
+	if (ns_separator != NULL) { 
+		ns_separator += 1;
+		lc_len = Z_STRLEN_P(zv) - (ns_separator - Z_STRVAL_P(zv));
+		lc_name = zend_str_tolower_dup(ns_separator, lc_len);
+		ZVAL_STRINGL(&c, lc_name, lc_len, 0);
+		lc_literal = zend_add_literal(CG(active_op_array), &c TSRMLS_CC);
+		CALCULATE_LITERAL_HASH(lc_literal);
+	}
 
 	return ret;
 }