since multiple impure parsers would corrupt yynerrs.
* data/push.c (yypstate_allocated): New static global variable
initialized to 0.
(yypull_parse): If yypstate_new returns 0, don't report it as memory
exhaustion if yypstate_allocated is 1, but still return 2.
(yypstate_new): Invoke yyerror and return 0 if yypstate_allocated is
already 1. Otherwise, set it to 1.
(yypstate_delete): Set it to 0.
* tests/push.at (Push Parsing: Multiple impure instances): New test
case.
name user variables starting with `yy'. Just pass NULL instead of a
dummy local &yylval to yypush_parse.
* tests/torture.at (AT_DATA_STACK_TORTURE): Do not name user variables
starting with `yy'.
<http://lists.gnu.org/archive/html/bug-bison/2007-07/msg00032.html>.
* THANKS: Add Brandon Lucia.
* data/push.c (yypstate_delete): Free the stack if it was reallocated
but the parse never completed and thus freed it.
* tests/Makefile.am (TESTSUITE_AT): Add push.at.
* tests/testsuite.at: Include push.at.
* test/push.at: New.
(Push Parsing: Memory Leak for Early Deletion): New test case.