From 3a4ea6cb9181de8386bbee6f0f5d76d6ca58866e Mon Sep 17 00:00:00 2001
From: Peter van Dommelen <pvandommelen@users.noreply.github.com>
Date: Sun, 30 May 2021 19:21:38 +0200
Subject: [PATCH] Don't automatically adjust memory_limit to 2M

As PHP has a minimum memory usage of 2M (size of allocator chunk),
setting a limit below that value is not meaningful and will be
automatically rounded up to the chunk size. Rather than doing this
silently, show the newly introduced error message.

The memory limit had to be increased to 2M for a number of tests.

tests/lang/bug45392 has been marked as XFAIL. This old bugfix is
not working as intended. The memory limit in main's `PG(memory_limit)`
differs from the one in zend_alloc. In zend_alloc the `AG(mm_heap)->limit`
is defined as `max(passed_value, ZEND_MM_CHUNK_SIZE)`. The check made in
an unclean shutdown will never be true unless the memory limit is lower
than ZEND_MM_CHUNK_SIZE, which happened to be the case in the test.
https://bugs.php.net/bug.php?id=45392
https://github.com/php/php-src/commit/fcc0fdd125fdb9e1713f91d027fe07d680a0cf36
---
 Zend/tests/fibers/out-of-memory-in-fiber.phpt           | 2 +-
 Zend/tests/fibers/out-of-memory-in-nested-fiber.phpt    | 2 +-
 Zend/tests/fibers/out-of-memory-in-recursive-fiber.phpt | 2 +-
 Zend/zend_alloc.c                                       | 3 ---
 ext/standard/tests/streams/bug78902.phpt                | 4 ++--
 tests/lang/bug45392.phpt                                | 4 +++-
 6 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/Zend/tests/fibers/out-of-memory-in-fiber.phpt b/Zend/tests/fibers/out-of-memory-in-fiber.phpt
index 8c8d0475ecc..4d31aa6f76a 100644
--- a/Zend/tests/fibers/out-of-memory-in-fiber.phpt
+++ b/Zend/tests/fibers/out-of-memory-in-fiber.phpt
@@ -1,7 +1,7 @@
 --TEST--
 Out of Memory in a fiber
 --INI--
-memory_limit=10K
+memory_limit=2M
 --SKIPIF--
 <?php
 if (getenv("USE_ZEND_ALLOC") === "0") {
diff --git a/Zend/tests/fibers/out-of-memory-in-nested-fiber.phpt b/Zend/tests/fibers/out-of-memory-in-nested-fiber.phpt
index daf1978df04..9e82b893fad 100644
--- a/Zend/tests/fibers/out-of-memory-in-nested-fiber.phpt
+++ b/Zend/tests/fibers/out-of-memory-in-nested-fiber.phpt
@@ -1,7 +1,7 @@
 --TEST--
 Out of Memory in a nested fiber
 --INI--
-memory_limit=10K
+memory_limit=2M
 --SKIPIF--
 <?php
 if (getenv("USE_ZEND_ALLOC") === "0") {
diff --git a/Zend/tests/fibers/out-of-memory-in-recursive-fiber.phpt b/Zend/tests/fibers/out-of-memory-in-recursive-fiber.phpt
index b5e340a12d9..bf711629229 100644
--- a/Zend/tests/fibers/out-of-memory-in-recursive-fiber.phpt
+++ b/Zend/tests/fibers/out-of-memory-in-recursive-fiber.phpt
@@ -1,7 +1,7 @@
 --TEST--
 Out of Memory from recursive fiber creation
 --INI--
-memory_limit=10K
+memory_limit=2M
 --SKIPIF--
 <?php
 if (getenv("USE_ZEND_ALLOC") === "0") {
diff --git a/Zend/zend_alloc.c b/Zend/zend_alloc.c
index 2f0de276bd3..55c4258374f 100644
--- a/Zend/zend_alloc.c
+++ b/Zend/zend_alloc.c
@@ -2661,9 +2661,6 @@ ZEND_API char* ZEND_FASTCALL zend_strndup(const char *s, size_t length)
 ZEND_API zend_result zend_set_memory_limit(size_t memory_limit)
 {
 #if ZEND_MM_LIMIT
-	if (memory_limit < ZEND_MM_CHUNK_SIZE) {
-		memory_limit = ZEND_MM_CHUNK_SIZE;
-	}
 	if (UNEXPECTED(memory_limit < AG(mm_heap)->real_size)) {
 		return FAILURE;
 	}
diff --git a/ext/standard/tests/streams/bug78902.phpt b/ext/standard/tests/streams/bug78902.phpt
index 1216c89bc27..c3ea8a52a16 100644
--- a/ext/standard/tests/streams/bug78902.phpt
+++ b/ext/standard/tests/streams/bug78902.phpt
@@ -1,14 +1,14 @@
 --TEST--
 Bug #78902: Memory leak when using stream_filter_append
 --INI--
-memory_limit=512k
+memory_limit=2M
 --FILE--
 <?php
 
 /** create temporary file 2mb file */
 $tmp_file_name = tempnam(sys_get_temp_dir(), 'test_');
 $fp = fopen($tmp_file_name, 'w+');
-$size = 1024 * 1024 * 2; // 2mb
+$size = 1024 * 1024 * 2; // 2mb, larger than the memory limit
 $chunk = 1024;
 while ($size > 0) {
     fputs($fp, str_pad('', min($chunk,$size)));
diff --git a/tests/lang/bug45392.phpt b/tests/lang/bug45392.phpt
index a9bdd40af2b..5940f7bc398 100644
--- a/tests/lang/bug45392.phpt
+++ b/tests/lang/bug45392.phpt
@@ -2,6 +2,8 @@
 Bug #45392 (ob_start()/ob_end_clean() and memory_limit)
 --INI--
 display_errors=stderr
+--XFAIL--
+The issue has not yet been resolved.
 --SKIPIF--
 <?php
 if (getenv("USE_ZEND_ALLOC") === "0") {
@@ -10,7 +12,7 @@ if (getenv("USE_ZEND_ALLOC") === "0") {
 --FILE--
 <?php
 echo __LINE__ . "\n";
-ini_set('memory_limit', 100);
+ini_set('memory_limit', "2M");
 ob_start();
 $i = 0;
 while($i++ < 5000)  {