From 93c3ec8b191402f4cb3b8b34afadb1999e774f6e Mon Sep 17 00:00:00 2001
From: "Christoph M. Becker" <cmbecker69@gmx.de>
Date: Sat, 20 Jul 2019 15:35:44 +0200
Subject: [PATCH] Fix #78308: IntlPartsIterator key is wrong for
 KEY_LEFT/KEY_RIGHT

We must not increase the iterator's index after it has been properly
determined.  A clean solution would be to increment the index in the
internal `*_move_forward()` methods instead of `IntlIterator::next()`,
but since the `*_move_forward()` methods are currently also called by
the internal `*_rewind()` methods, and don't have a flag to determine
the (intent of the) caller, we apply a hack for now.

We also fix the erroneous expectations of an existing test case.
---
 .../breakiterator/breakiterator_iterators.cpp |  4 +--
 .../breakiter_getPartsIterator_var1.phpt      | 16 ++++-----
 ext/intl/tests/bug78308.phpt                  | 34 +++++++++++++++++++
 3 files changed, 44 insertions(+), 10 deletions(-)
 create mode 100644 ext/intl/tests/bug78308.phpt

diff --git a/ext/intl/breakiterator/breakiterator_iterators.cpp b/ext/intl/breakiterator/breakiterator_iterators.cpp
index bdf1b3e53f37e..aac64547ef9bc 100644
--- a/ext/intl/breakiterator/breakiterator_iterators.cpp
+++ b/ext/intl/breakiterator/breakiterator_iterators.cpp
@@ -160,9 +160,9 @@ static void _breakiterator_parts_move_forward(zend_object_iterator *iter)
 	}
 
 	if (zoi_bit->key_type == PARTS_ITERATOR_KEY_LEFT) {
-		iter->index = cur;
+		iter->index = cur ? cur - 1 : cur;   /* HACK: cater to increment in next(), but not rewind() */
 	} else if (zoi_bit->key_type == PARTS_ITERATOR_KEY_RIGHT) {
-		iter->index = next;
+		iter->index = cur ? next - 1 : next; /* HACK: cater to increment in next(), but not rewind() */
 	}
 	/* else zoi_bit->key_type == PARTS_ITERATOR_KEY_SEQUENTIAL
 	 * No need to do anything, the engine increments ->index */
diff --git a/ext/intl/tests/breakiter_getPartsIterator_var1.phpt b/ext/intl/tests/breakiter_getPartsIterator_var1.phpt
index 7bbd27ea45112..78e4b2fb0ffea 100644
--- a/ext/intl/tests/breakiter_getPartsIterator_var1.phpt
+++ b/ext/intl/tests/breakiter_getPartsIterator_var1.phpt
@@ -36,25 +36,25 @@ array(5) {
 array(5) {
   [0]=>
   string(3) "foo"
-  [4]=>
+  [3]=>
   string(1) " "
-  [5]=>
+  [4]=>
   string(3) "bar"
-  [8]=>
+  [7]=>
   string(1) " "
-  [9]=>
+  [8]=>
   string(3) "tao"
 }
 array(5) {
   [3]=>
   string(3) "foo"
-  [5]=>
+  [4]=>
   string(1) " "
-  [8]=>
+  [7]=>
   string(3) "bar"
-  [9]=>
+  [8]=>
   string(1) " "
-  [12]=>
+  [11]=>
   string(3) "tao"
 }
 ==DONE==
diff --git a/ext/intl/tests/bug78308.phpt b/ext/intl/tests/bug78308.phpt
new file mode 100644
index 0000000000000..5618c84859633
--- /dev/null
+++ b/ext/intl/tests/bug78308.phpt
@@ -0,0 +1,34 @@
+--TEST--
+Bug #78308 (IntlPartsIterator key is wrong for KEY_LEFT/KEY_RIGHT)
+--SKIPIF--
+<?php
+if (!extension_loaded('intl')) die('skip intl extension not available');
+?>
+--FILE--
+<?php
+$iter = \IntlBreakIterator::createCodePointInstance();
+$iter->setText('ABC');
+echo "KEY_LEFT:\n";
+foreach ($iter->getPartsIterator(\IntlPartsIterator::KEY_LEFT) as $key => $value) {
+    var_dump($key, $value);
+}
+echo "KEY_RIGHT:\n";
+foreach ($iter->getPartsIterator(\IntlPartsIterator::KEY_RIGHT) as $key => $value) {
+    var_dump($key, $value);
+}
+?>
+--EXPECT--
+KEY_LEFT:
+int(0)
+string(1) "A"
+int(1)
+string(1) "B"
+int(2)
+string(1) "C"
+KEY_RIGHT:
+int(1)
+string(1) "A"
+int(2)
+string(1) "B"
+int(3)
+string(1) "C"