Grow the JIT stack if it becomes exhausted

Problem reported by Oliver Freyermuth in: http://bugs.gnu.org/19833
* NEWS: Document the fix.
* tests/Makefile.am (TESTS): Add pcre-jitstack.
* tests/pcre-jitstack: New file.
* src/pcresearch.c (NSUB): Move decl earlier, since it's needed
earlier now.
(jit_stack_size) [PCRE_STUDY_JIT_COMPILE]: New static var.
(jit_exec): New function.
(Pcompile): Initialize jit_stack_size.
(Pexecute): Use new jit_exec function.  Report a useful diagnostic
if the error is PCRE_ERROR_JIT_STACKLIMIT.

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/pcre-jitstack b/tests/pcre-jitstack
new file mode 100755
index 00000000..03587f1a
--- /dev/null
+++ b/tests/pcre-jitstack
@@ -0,0 +1,39 @@
+#! /bin/sh
+# Grep 2.21 would report "grep: internal PCRE error: -27"
+#
+# Copyright 2015 Free Software Foundation, Inc.
+#
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+require_pcre_
+
+nl_base64=$(echo | (base64) 2>/dev/null) && test "X$nl_base64" = XCg== ||
+  skip_ "your system lacks the base64 program"
+foo=$( (echo foo | gzip | gzip -d) 2>/dev/null) && test "X$foo" = Xfoo ||
+  skip_ "your system lacks the gzip program"
+
+fail=0
+
+base64 -d >pcrejit.txt.gz <<'EOF'
+H4sIAAAAAAACA+2bUU4DMQxE/7mMz5T7XwKE+IBKVLue58yk0B9EtX6xJxN7t4VaH69a6+tHrW+/
+r4e3n75KARWShSOFTtiumE3FPVyo79ATIJ0Ry0No/yXe99UIUqTGKKUzYHFJHJoaCONQDCnDSCDS
+IPAvGCVeXNsZ7lpbWFfdaZtgPos5LeK2C1TBKzD09V3HFlCOsbFT/hNbz4HzJaRjnjdam9FXw/o6
+VyPozhMmiaRYAMeNSJR1iMjBEFLMtsH7lptartfxkzPQgFVofwRlxKsMYn2KNDnU9fsOQCkRIYVT
+G80ZRqBpSQjRYPX7s9gvtqknyNE2f8V09sxHM7YPmMMJgrmVna2AT717n5fUAIDkiBCqFgWUUgKD
+8jOc0Rgj5JS6vZnQI14wkaTDAkD266p/iVHs8gjCrMFARVM0iEVgFAa9YRAQT4tkgsmloTJLmyCm
+uSHRnTkzIdZMmZ5kYX/iJFtTwu9cFvr3aDWcUx4pUW/cVQwPoQSlwguNd4M0vTpAauKodmLFXv1P
+dkcKkYUglER2Q4L4gnmOiNGzSBATwGQgwihs5/QffIhyfg4hJvM2r4Rp6L+1ibCCd4jYZ6jCiBlc
+2+y4fl4yTGIwcWXNAUEeXmu8iCMV96DNTnmRNICDk2N5qaXGbsF91OX/0hlcYTjrMfy02p9Xv70D
+mv3RZCFOAAA=
+EOF
+test $? -eq 0 || framework_failure_
+
+gzip -d pcrejit.txt || framework_failure_
+
+LC_ALL=C grep -P -n '^([/](?!/)|[^/])*~/.*' pcrejit.txt
+test $? -eq 1 || fail=1
+
+Exit $fail