Fix cache validity check of require

* array.c (rb_ary_shared_with_p): fix cache validity check.
  If #pop or #shift has been called against $: or $", the array will
  be still shared with the snapshot. We check array length for cache
  validity.
  [ruby-core:49518] [Bug #7383]

* test/ruby/test_require.rb
  (TestRequire#test_require_with_array_pop,
   TestRequire#test_require_with_array_shift): add tests for above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37808 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 7 insertions, 4 deletions

diff --git a/array.c b/array.c
index bbe9f60e40..3e617f55aa 100644
--- a/array.c
+++ b/array.c
@@ -351,13 +351,16 @@ rb_ary_frozen_p(VALUE ary)
    e.g. rb_ary_replace) and check later whether the array has been
    modified from the snapshot.  The snapshot is cheap, though if
    something does modify the array it will pay the cost of copying
-   it. */
+   it.  If Array#pop or Array#shift has been called, the array will
+   be still shared with the snapshot, but the array length will
+   differ. */
 VALUE
 rb_ary_shared_with_p(VALUE ary1, VALUE ary2)
 {
-    if (!ARY_EMBED_P(ary1) && ARY_SHARED_P(ary1)
-     && !ARY_EMBED_P(ary2) && ARY_SHARED_P(ary2)
-     && RARRAY(ary1)->as.heap.aux.shared == RARRAY(ary2)->as.heap.aux.shared) {
+    if (!ARY_EMBED_P(ary1) && ARY_SHARED_P(ary1) &&
+	!ARY_EMBED_P(ary2) && ARY_SHARED_P(ary2) &&
+	RARRAY(ary1)->as.heap.aux.shared == RARRAY(ary2)->as.heap.aux.shared &&
+	RARRAY(ary1)->as.heap.len == RARRAY(ary2)->as.heap.len) {
 	return Qtrue;
     }
     return Qfalse;