Fix compiling regular expressions like /\X*(?0)/

perl-5.24.0-fix-128109-do-not-move-RExC_open_parens-0-in-reginse.patch

@@ -0,0 +1,123 @@
+From c6e7032a63f2162405644582af6600dcb5ba66d1 Mon Sep 17 00:00:00 2001
+From: Yves Orton <demerphq@gmail.com>
+Date: Tue, 10 May 2016 09:44:31 +0200
+Subject: [PATCH] fix #128109 - do not move RExC_open_parens[0] in reginsert
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Petr Pisar: Two commits ported to 5.24.0:
+
+commit da7cf1cc7cedc01f35ceb6724e8260c3b0ee0d12
+Author: Yves Orton <demerphq@gmail.com>
+Date:   Tue May 10 09:44:31 2016 +0200
+
+    fix #128109 - do not move RExC_open_parens[0] in reginsert
+
+    In d5a00e4af6b155495be31a35728b8fef8e671ebe I merged GOSUB and GOSTART,
+    part of which involved making RExC_open_parens[0] refer to the start of
+    the pattern, and RExC_close_parens[0] referring to the end of the pattern.
+
+    This tripped up in reginsert in a subtle way, the start of the pattern
+    cannot and should not move in reginsert(). Unlike a paren that might
+    be at the start of the pattern which should move when something is inserted
+    in front of it, the start is a fixed point and should never move.
+
+    This patches fixes this up, and adds an assert to check that reginsert()
+    is not called once study_chunk() starts, as reginsert() does not adjust
+    RExC_recurse.
+
+    This was noticed by hv while debugging [perl #128085], thanks hugo!
+
+commit ec5bd2262bb4e28f0dc6a0a3edb9b1f1b5befa2f
+Author: Dan Collins <dcollinsn@gmail.com>
+Date:   Fri Jun 17 19:40:57 2016 -0400
+
+    Add tests for regex recursion
+
+    d5a00e4af introduced a bug in reginsert that was fixed by da7cf1cc7,
+    originally documented in [perl #128109]. This patch adds two
+    regression tests for the testcase reported by Jan Goyvaerts in
+    [perl #128420].
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ regcomp.c     | 13 +++++++++++--
+ t/re/re_tests |  2 ++
+ 2 files changed, 13 insertions(+), 2 deletions(-)
+
+diff --git a/regcomp.c b/regcomp.c
+index f29892c..7462885 100644
+--- a/regcomp.c
++++ b/regcomp.c
+@@ -223,6 +223,7 @@ struct RExC_state_t {
+ #endif
+     bool        seen_unfolded_sharp_s;
+     bool        strict;
++    bool        study_started;
+ };
+ 
+ #define RExC_flags	(pRExC_state->flags)
+@@ -289,6 +290,7 @@ struct RExC_state_t {
+ #define RExC_frame_last (pRExC_state->frame_last)
+ #define RExC_frame_count (pRExC_state->frame_count)
+ #define RExC_strict (pRExC_state->strict)
++#define RExC_study_started      (pRExC_state->study_started)
+ #define RExC_warn_text (pRExC_state->warn_text)
+ 
+ /* Heuristic check on the complexity of the pattern: if TOO_NAUGHTY, we set
+@@ -4104,6 +4106,7 @@ S_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp,
+     GET_RE_DEBUG_FLAGS_DECL;
+ 
+     PERL_ARGS_ASSERT_STUDY_CHUNK;
++    RExC_study_started= 1;
+ 
+ 
+     if ( depth == 0 ) {
+@@ -6886,6 +6889,7 @@ Perl_re_op_compile(pTHX_ SV ** const patternp, int pat_count,
+     RExC_contains_locale = 0;
+     RExC_contains_i = 0;
+     RExC_strict = cBOOL(pm_flags & RXf_PMf_STRICT);
++    RExC_study_started = 0;
+     pRExC_state->runtime_code_qr = NULL;
+     RExC_frame_head= NULL;
+     RExC_frame_last= NULL;
+@@ -18240,7 +18244,9 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
+ 	RExC_size += size;
+ 	return;
+     }
+-
++    assert(!RExC_study_started); /* I believe we should never use reginsert once we have started
++                                    studying. If this is wrong then we need to adjust RExC_recurse
++                                    below like we do with RExC_open_parens/RExC_close_parens. */
+     src = RExC_emit;
+     RExC_emit += size;
+     dst = RExC_emit;
+@@ -18251,7 +18257,10 @@ S_reginsert(pTHX_ RExC_state_t *pRExC_state, U8 op, regnode *opnd, U32 depth)
+          * iow it is 1 more than the number of parens seen in
+          * the pattern so far. */
+         for ( paren=0 ; paren < RExC_npar ; paren++ ) {
+-            if ( RExC_open_parens[paren] >= opnd ) {
++            /* note, RExC_open_parens[0] is the start of the
++             * regex, it can't move. RExC_close_parens[0] is the end
++             * of the regex, it *can* move. */
++            if ( paren && RExC_open_parens[paren] >= opnd ) {
+                 /*DEBUG_PARSE_FMT("open"," - %d",size);*/
+                 RExC_open_parens[paren] += size;
+             } else {
+diff --git a/t/re/re_tests b/t/re/re_tests
+index 34ac94a..7e8522d 100644
+--- a/t/re/re_tests
++++ b/t/re/re_tests
+@@ -1966,6 +1966,8 @@ ab(?#Comment){2}c	abbc	y	$&	abbc
+ .{1}??	-	c	-	Nested quantifiers
+ .{1}?+	-	c	-	Nested quantifiers
+ (?:.||)(?|)000000000@	000000000@	y	$&	000000000@		#  [perl #126405]
++aa$|a(?R)a|a	aaa	y	$&	aaa		# [perl 128420] recursive matches
++(?:\1|a)([bcd])\1(?:(?R)|e)\1	abbaccaddedcb	y	$&	abbaccaddedcb		# [perl 128420] recursive match with backreferences
+ 
+ # Keep these lines at the end of the file
+ # vim: softtabstop=0 noexpandtab
+-- 
+2.5.5
+

perl.spec

@@ -28,7 +28,7 @@
 Name:           perl
 Version:        %{perl_version}
 # release number must be even higher, because dual-lived modules will be broken otherwise
-Release:        366%{?dist}
+Release:        367%{?dist}
 Epoch:          %{perl_epoch}
 Summary:        Practical Extraction and Report Language
 Group:          Development/Languages
@@ -121,6 +121,10 @@ Patch31:        perl-5.24.0-Fix-a-memory-leak-in-strict-regex-posix-classes.patc
 # in upstream after 5.25.1
 Patch32:        perl-5.25.1-perl-128316-preserve-errno-from-failed-system-calls.patch
 
+# Fix compiling regular expressions like /\X*(?0)/, RT#128109, in upstream
+# after 5.25.1
+Patch33:        perl-5.24.0-fix-128109-do-not-move-RExC_open_parens-0-in-reginse.patch
+
 # Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
 Patch200:       perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
 
@@ -2772,6 +2776,7 @@ Perl extension for Version Objects
 %patch30 -p1
 %patch31 -p1
 %patch32 -p1
+%patch33 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -2795,6 +2800,7 @@ perl -x patchlevel.h \
     'Fedora Patch30: Replace EU::MakeMaker dependency with EU::MM::Utils in IPC::Cmd (bug #1129443)' \
     'Fedora Patch31: Fix a memory leak in compiling a POSIX class (RT#128313)' \
     'Fedora Patch32: Do not mangle errno from failed socket calls (RT#128316)' \
+    'Fedora Patch33: Fix compiling regular expressions like /\X*(?0)/ (RT#128109)' \
     'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \
     'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
     %{nil}
@@ -5061,6 +5067,9 @@ popd
 
 # Old changelog entries are preserved in CVS.
 %changelog
+* Mon Jun 20 2016 Petr Pisar <ppisar@redhat.com> - 4:5.24.0-367
+- Fix compiling regular expressions like /\X*(?0)/ (RT#128109)
+
 * Thu Jun 16 2016 Petr Pisar <ppisar@redhat.com> - 4:5.24.0-366
 - Do not mangle errno from failed socket calls (RT#128316)