Fixed bug #78506

NEWS

@@ -25,6 +25,10 @@ PHP                                                                        NEWS
   . Fixed bug #78510 (Partially uninitialized buffer returned by
     sodium_crypto_generichash_init()). (Frank Denis, cmb)
 
+- Standard:
+  . Fixed bug #78506 (Error in a php_user_filter::filter() is not reported).
+    (Nikita)
+
 05 Sep 2019, PHP 7.4.0RC1
 
 - Core:

ext/standard/tests/streams/bug78506.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Bug #78506: Error in a php_user_filter::filter() is not reported
+--FILE--
+<?php
+
+class MyFilter extends php_user_filter {
+    public function filter($in, $out, &$consumed, $closing)
+    {
+        stream_bucket_make_writeable($in);
+        return PSFS_ERR_FATAL;
+    }
+
+}
+
+stream_filter_register('filtername', MyFilter::class);
+
+$source_resource = fopen('php://memory', 'rb+');
+fwrite($source_resource, 'Test data');
+rewind($source_resource);
+
+stream_filter_prepend($source_resource,'filtername',STREAM_FILTER_READ);
+
+var_dump(stream_copy_to_stream($source_resource, fopen('php://memory', 'wb')));
+
+?>
+--EXPECT--
+bool(false)

main/streams/streams.c

@@ -1586,33 +1586,31 @@ PHPAPI int _php_stream_copy_to_stream_ex(php_stream *src, php_stream *dest, size
 	while(1) {
 		size_t readchunk = sizeof(buf);
 		ssize_t didread;
+		char *writeptr;
 
 		if (maxlen && (maxlen - haveread) < readchunk) {
 			readchunk = maxlen - haveread;
 		}
 
 		didread = php_stream_read(src, buf, readchunk);
+		if (didread <= 0) {
+			*len = haveread;
+			return didread < 0 ? FAILURE : SUCCESS;
+		}
 
-		if (didread > 0) {
-			/* extra paranoid */
-			char *writeptr;
+		towrite = didread;
+		writeptr = buf;
+		haveread += didread;
 
-			towrite = didread;
-			writeptr = buf;
-			haveread += didread;
-
-			while (towrite) {
-				ssize_t didwrite = php_stream_write(dest, writeptr, towrite);
-				if (didwrite <= 0) {
-					*len = haveread - (didread - towrite);
-					return FAILURE;
-				}
-
-				towrite -= didwrite;
-				writeptr += didwrite;
+		while (towrite) {
+			ssize_t didwrite = php_stream_write(dest, writeptr, towrite);
+			if (didwrite <= 0) {
+				*len = haveread - (didread - towrite);
+				return FAILURE;
 			}
-		} else {
-			break;
+
+			towrite -= didwrite;
+			writeptr += didwrite;
 		}
 
 		if (maxlen - haveread == 0) {