X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d2d1b42b0730316f4f70eb416dcc767ffaaa2019..37c82725c8235e260f68f14308370be2d75f56dd:/tests/regression.at

diff --git a/tests/regression.at b/tests/regression.at
index f141c4b8..70e3420b 100644
--- a/tests/regression.at
+++ b/tests/regression.at
@@ -611,3 +611,78 @@ AT_CLEANUP
 
 AT_TEST_CPP_GUARD_H([input/input])
 AT_TEST_CPP_GUARD_H([9foo])
+
+
+## ---------------- ##
+## Broken Closure.  ##
+## ---------------- ##
+
+# TC was once broken during a massive `simplification' of the code.
+# It resulted in bison dumping core on the following grammar (the
+# computation of FIRSTS uses TC).  It managed to produce a pretty
+# exotic closure:
+#
+# TC: Input
+#
+#    01234567
+#   +--------+
+#  0| 1      |
+#  1|  1     |
+#  2|   1    |
+#  3|    1   |
+#  4|     1  |
+#  5|      1 |
+#  6|       1|
+#  7|        |
+#   +--------+
+#
+# TC: Output
+#
+#    01234567
+#   +--------+
+#  0| 1      |
+#  1| 111    |
+#  2| 111    |
+#  3| 1111   |
+#  4| 111 1  |
+#  5| 111  1 |
+#  6| 111   1|
+#  7| 111    |
+#   +--------+
+#
+# instead of that below.
+
+AT_SETUP([Broken Closure])
+
+AT_DATA([input.y],
+[[%%
+a: b
+b: c
+c: d
+d: e
+e: f
+f: g
+g: h
+h: 'h'
+]])
+
+AT_CHECK([bison --trace input.y 2>&1 |
+          sed -n '/^TC: Output BEGIN/,/^TC: Output END/p'],
+         [0],
+[[TC: Output BEGIN
+           @&t@
+   01234567
+  +--------+
+ 0| 1111111|
+ 1|  111111|
+ 2|   11111|
+ 3|    1111|
+ 4|     111|
+ 5|      11|
+ 6|       1|
+ 7|        |
+  +--------+
+TC: Output END
+]])
+
+AT_CLEANUP