From a3e52afebe77517ca10d98ba57fefe3f178d56b6 Mon Sep 17 00:00:00 2001
From: Dmitry Stogov <dmitry@zend.com>
Date: Fri, 29 Mar 2019 00:02:26 +0300
Subject: [PATCH] Fixed bug #77768 (FFI: Builtin Types Should Not Raise Error
 On Redeclaration)

---
 ext/ffi/ffi.c               | 30 +++++++++++++++++++++++++++-
 ext/ffi/tests/bug77768.phpt | 39 +++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 ext/ffi/tests/bug77768.phpt

diff --git a/ext/ffi/ffi.c b/ext/ffi/ffi.c
index ba15151dd5..e8061a4682 100644
--- a/ext/ffi/ffi.c
+++ b/ext/ffi/ffi.c
@@ -5772,11 +5772,39 @@ void zend_ffi_declare(const char *name, size_t name_len, zend_ffi_dcl *dcl) /* {
 		FFI_G(symbols) = pemalloc(sizeof(HashTable), FFI_G(persistent));
 		zend_hash_init(FFI_G(symbols), 0, NULL, FFI_G(persistent) ? zend_ffi_symbol_hash_persistent_dtor : zend_ffi_symbol_hash_dtor, FFI_G(persistent));
 	}
+	zend_ffi_finalize_type(dcl);
 	sym = zend_hash_str_find_ptr(FFI_G(symbols), name, name_len);
 	if (sym) {
+		if ((dcl->flags & ZEND_FFI_DCL_STORAGE_CLASS) == ZEND_FFI_DCL_TYPEDEF
+		 && sym->kind == ZEND_FFI_SYM_TYPE
+		 && zend_ffi_is_same_type(ZEND_FFI_TYPE(sym->type), ZEND_FFI_TYPE(dcl->type))
+		 && sym->is_const == (zend_bool)(dcl->attr & ZEND_FFI_ATTR_CONST)) {
+			/* allowed redeclaration */
+			zend_ffi_type_dtor(dcl->type);
+			return;
+		} else if ((dcl->flags & ZEND_FFI_DCL_STORAGE_CLASS) == 0
+		 || (dcl->flags & ZEND_FFI_DCL_STORAGE_CLASS) == ZEND_FFI_DCL_EXTERN) {
+			zend_ffi_type *type = ZEND_FFI_TYPE(dcl->type);
+
+			if (type->kind == ZEND_FFI_TYPE_FUNC) {
+				if (sym->kind == ZEND_FFI_SYM_FUNC
+				 && zend_ffi_same_types(ZEND_FFI_TYPE(sym->type), type)) {
+					/* allowed redeclaration */
+					zend_ffi_type_dtor(dcl->type);
+					return;
+				}
+			} else {
+				if (sym->kind == ZEND_FFI_SYM_VAR
+				 && zend_ffi_is_same_type(ZEND_FFI_TYPE(sym->type), type)
+				 && sym->is_const == (zend_bool)(dcl->attr & ZEND_FFI_ATTR_CONST)) {
+					/* allowed redeclaration */
+					zend_ffi_type_dtor(dcl->type);
+					return;
+				}
+			}
+		}
 		zend_ffi_parser_error("redeclaration of '%.*s' at line %d", name_len, name, FFI_G(line));
 	} else {
-		zend_ffi_finalize_type(dcl);
 		if ((dcl->flags & ZEND_FFI_DCL_STORAGE_CLASS) == ZEND_FFI_DCL_TYPEDEF) {
 			if (zend_ffi_validate_vla(ZEND_FFI_TYPE(dcl->type)) != SUCCESS) {
 				zend_ffi_cleanup_dcl(dcl);
diff --git a/ext/ffi/tests/bug77768.phpt b/ext/ffi/tests/bug77768.phpt
new file mode 100644
index 0000000000..6c29db59d7
--- /dev/null
+++ b/ext/ffi/tests/bug77768.phpt
@@ -0,0 +1,39 @@
+--TEST--
+Bug #77768 (Redeclaration of builtin types and repeated declarations)
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+try {
+	$libc = FFI::cdef("int printf(const char *format, ...);", "libc.so.6");
+} catch (Throwable $_) {
+	die('skip libc.so.6 not available');
+}
+?>
+--INI--
+ffi.enable=1
+--FILE--
+<?php
+$x = FFI::cdef("
+typedef __builtin_va_list __gnuc_va_list;
+typedef unsigned int uint8_t;
+
+typedef int64_t a;
+typedef int64_t b;
+typedef a c;
+typedef b c;
+
+struct point {int x,y;};
+
+typedef struct point d;
+typedef struct point d;
+
+int printf(const char *format, ...);
+int printf(const char *format, ...);
+");
+
+var_dump(FFI::sizeof($x->new("uint8_t")));
+var_dump(FFI::sizeof(FFI::new("uint8_t")));
+?>
+--EXPECT--
+int(4)
+int(1)
-- 
2.40.0