PHPC-613, PHPC-615: Improve toJSON() error handling

src/bson.c

@@ -1583,10 +1583,19 @@ PHP_FUNCTION(toJSON)
 		char   *str;
 		size_t  str_len;
 		str = bson_as_json(b, &str_len);
+
+		if (!str) {
+			phongo_throw_exception(PHONGO_ERROR_UNEXPECTED_VALUE TSRMLS_CC, "Could not convert BSON document to a JSON string");
+			bson_reader_destroy(reader);
+			return;
+		}
+
 		PHONGO_RETVAL_STRINGL(str, str_len);
 		bson_free(str);
 	} else {
 		phongo_throw_exception(PHONGO_ERROR_UNEXPECTED_VALUE TSRMLS_CC, "Could not read document from BSON reader");
+		bson_reader_destroy(reader);
+		return;
 	}
 
 	if (bson_reader_read(reader, &eof) || !eof) {

tests/bson/bson-toJSON_error-001.phpt

@@ -6,8 +6,8 @@ BSON\toJSON(): BSON decoding exceptions
 <?php
 require_once __DIR__ . "/../utils/basic.inc";
 
-/* We can't really test for bson_iter_init() failure, since bson_reader_read()
- * already checks that the buffer is at least 5 bytes.
+/* We can't really test for bson_iter_init() failure within bson_as_json(),
+ * since bson_reader_read() already checks that the buffer is at least 5 bytes.
  */
 $invalidBson = array(
     '',

tests/bson/bson-toJSON_error-002.phpt

@@ -0,0 +1,28 @@
+--TEST--
+BSON\toJSON(): BSON decoding exceptions for malformed documents
+--SKIPIF--
+<?php require __DIR__ . "/../utils/basic-skipif.inc"?>
+--FILE--
+<?php
+require_once __DIR__ . "/../utils/basic.inc";
+
+$tests = array(
+    pack('Vx', 4), // Empty document with invalid length (too small)
+    pack('Vx', 6), // Empty document with invalid length (too large)
+);
+
+foreach ($tests as $bson) {
+    echo throws(function() use ($bson) {
+        toJSON($bson);
+    }, 'MongoDB\Driver\Exception\UnexpectedValueException'), "\n";
+}
+
+?>
+===DONE===
+<?php exit(0); ?>
+--EXPECTF--
+OK: Got MongoDB\Driver\Exception\UnexpectedValueException
+Could not read document from BSON reader
+OK: Got MongoDB\Driver\Exception\UnexpectedValueException
+Could not read document from BSON reader
+===DONE===

tests/bson/bson-toJSON_error-003.phpt

@@ -0,0 +1,39 @@
+--TEST--
+BSON\toJSON(): BSON decoding exceptions for bson_as_json() failure
+--SKIPIF--
+<?php require __DIR__ . "/../utils/basic-skipif.inc"?>
+--FILE--
+<?php
+require_once __DIR__ . "/../utils/basic.inc";
+
+$tests = array(
+    // Invalid UTF-8 characters (i.e. 0xFE, 0xFF) in field name
+    pack('VCCCxVa*xx', 17, 2, 254, 255, 3, 'bar'),
+    /* Note: we don't use a three-character string in the underflow case, as
+     * the 4-byte string length and payload (i.e. three characters + null byte)
+     * coincidentally satisfy the expected size for an 8-byte double. We also
+     * don't use a four-character string, since its null byte would be
+     * interpreted as the document terminator. The actual document terminator
+     * would then remain in the buffer and trigger a "did not exhaust" error.
+     */
+    pack('VCa*xVa*xx', 17, 1, 'foo', 3, 'ab'), // Invalid field type (underflow)
+    pack('VCa*xVa*xx', 20, 1, 'foo', 6, 'abcde'), // Invalid field type (overflow)
+);
+
+foreach ($tests as $bson) {
+    echo throws(function() use ($bson) {
+        toJSON($bson);
+    }, 'MongoDB\Driver\Exception\UnexpectedValueException'), "\n";
+}
+
+?>
+===DONE===
+<?php exit(0); ?>
+--EXPECTF--
+OK: Got MongoDB\Driver\Exception\UnexpectedValueException
+Could not convert BSON document to a JSON string
+OK: Got MongoDB\Driver\Exception\UnexpectedValueException
+Could not convert BSON document to a JSON string
+OK: Got MongoDB\Driver\Exception\UnexpectedValueException
+Could not convert BSON document to a JSON string
+===DONE===