Fix bug #66773, #66862

This a partial backport of 8754b19. It
a) fixes the class/function/constant import table confusion in the
   namespaced case, and
b) restricts conflict checks to a single file based on a filename
   pointer comparison.

It does not fix the issues with filename reuse (e.g. due to eval)
and late-bound classes. This part of the change requires globals
changes.

6 files changed, 75 insertions, 34 deletions

diff --git a/NEWS b/NEWS
index 0b4cae7cf6..8117d60f2d 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,9 @@ PHP                                                                        NEWS
 - Core:
   . Fixed bug #73181 (parse_str() without a second argument leads to crash).
     (Nikita)
+  . Fixed bug #66773 (Autoload with Opcache allows importing conflicting class
+    name to namespace). (Nikita)
+  . Fixed bug #66862 ((Sub-)Namespaces unexpected behaviour). (Nikita)
 
 - GD:
   . Fixed bug #73213 (Integer overflow in imageline() with antialiasing). (cmb)
diff --git a/Zend/tests/use_function/no_conflict_with_classes.phpt b/Zend/tests/use_function/no_conflict_with_classes.phpt
new file mode 100644
index 0000000000..bde94afb03
--- /dev/null
+++ b/Zend/tests/use_function/no_conflict_with_classes.phpt
@@ -0,0 +1,15 @@
+--TEST--
+"use function" should not conflict with class names
+--FILE--
+<?php
+
+namespace Foo;
+
+class Bar {}
+
+use function bar;
+
+?>
+===DONE===
+--EXPECT--
+===DONE===
diff --git a/Zend/tests/use_no_file_conflict.phpt b/Zend/tests/use_no_file_conflict.phpt
new file mode 100644
index 0000000000..9423995af3
--- /dev/null
+++ b/Zend/tests/use_no_file_conflict.phpt
@@ -0,0 +1,12 @@
+--TEST--
+Use conflicts should not occur across files
+--FILE--
+<?php
+
+require __DIR__ . '/use_no_file_conflict_1.inc';
+require __DIR__ . '/use_no_file_conflict_2.inc';
+
+?>
+===DONE===
+--EXPECT--
+===DONE===
diff --git a/Zend/tests/use_no_file_conflict_1.inc b/Zend/tests/use_no_file_conflict_1.inc
new file mode 100644
index 0000000000..c2739ff64d
--- /dev/null
+++ b/Zend/tests/use_no_file_conflict_1.inc
@@ -0,0 +1,4 @@
+<?php
+
+namespace Foo;
+class A {}
diff --git a/Zend/tests/use_no_file_conflict_2.inc b/Zend/tests/use_no_file_conflict_2.inc
new file mode 100644
index 0000000000..badcc85bea
--- /dev/null
+++ b/Zend/tests/use_no_file_conflict_2.inc
@@ -0,0 +1,4 @@
+<?php
+
+namespace Foo;
+use A;
diff --git a/Zend/zend_compile.c b/Zend/zend_compile.c
index 53cafcb56d..eb373906eb 100644
--- a/Zend/zend_compile.c
+++ b/Zend/zend_compile.c
@@ -5499,6 +5499,41 @@ static void zend_check_already_in_use(uint32_t type, zend_string *old_name, zend
 }
 /* }}} */
 
+static void zend_check_use_conflict(
+		uint32_t type, zend_string *old_name, zend_string *new_name, zend_string *lookup_name) {
+	switch (type) {
+		case T_CLASS:
+		{
+			zend_class_entry *ce = zend_hash_find_ptr(CG(class_table), lookup_name);
+			if (ce && ce->type == ZEND_USER_CLASS
+				&& ce->info.user.filename == CG(compiled_filename)
+			) {
+				zend_check_already_in_use(type, old_name, new_name, lookup_name);
+			}
+			break;
+		}
+		case T_FUNCTION:
+		{
+			zend_function *fn = zend_hash_find_ptr(CG(function_table), lookup_name);
+			if (fn && fn->type == ZEND_USER_FUNCTION
+				&& fn->op_array.filename == CG(compiled_filename)
+			) {
+				zend_check_already_in_use(type, old_name, new_name, lookup_name);
+			}
+			break;
+		}
+		case T_CONST:
+		{
+			zend_string *filename = zend_hash_find_ptr(&CG(const_filenames), lookup_name);
+			if (filename && filename == CG(compiled_filename)) {
+				zend_check_already_in_use(type, old_name, new_name, lookup_name);
+			}
+			break;
+		}
+		EMPTY_SWITCH_DEFAULT_CASE()
+	}
+}
+
 void zend_compile_use(zend_ast *ast) /* {{{ */
 {
 	zend_ast_list *list = zend_ast_get_list(ast);
@@ -5555,43 +5590,11 @@ void zend_compile_use(zend_ast *ast) /* {{{ */
 			ZSTR_VAL(ns_name)[ZSTR_LEN(current_ns)] = '\\';
 			memcpy(ZSTR_VAL(ns_name) + ZSTR_LEN(current_ns) + 1, ZSTR_VAL(lookup_name), ZSTR_LEN(lookup_name));
 
-			if (zend_hash_exists(CG(class_table), ns_name)) {
-				zend_check_already_in_use(type, old_name, new_name, ns_name);
-			}
+			zend_check_use_conflict(type, old_name, new_name, ns_name);
 
 			zend_string_free(ns_name);
 		} else {
-			switch (type) {
-				case T_CLASS:
-				{
-					zend_class_entry *ce = zend_hash_find_ptr(CG(class_table), lookup_name);
-					if (ce && ce->type == ZEND_USER_CLASS
-						&& ce->info.user.filename == CG(compiled_filename)
-					) {
-						zend_check_already_in_use(type, old_name, new_name, lookup_name);
-					}
-					break;
-				}
-				case T_FUNCTION:
-				{
-					zend_function *fn = zend_hash_find_ptr(CG(function_table), lookup_name);
-					if (fn && fn->type == ZEND_USER_FUNCTION
-						&& fn->op_array.filename == CG(compiled_filename)
-					) {
-						zend_check_already_in_use(type, old_name, new_name, lookup_name);
-					}
-					break;
-				}
-				case T_CONST:
-				{
-					zend_string *filename = zend_hash_find_ptr(&CG(const_filenames), lookup_name);
-					if (filename && filename == CG(compiled_filename)) {
-						zend_check_already_in_use(type, old_name, new_name, lookup_name);
-					}
-					break;
-				}
-				EMPTY_SWITCH_DEFAULT_CASE()
-			}
+			zend_check_use_conflict(type, old_name, new_name, lookup_name);
 		}
 
 		zend_string_addref(old_name);