Revision: 697
http://vcs.pcre.org/viewvc?view=rev&revision=697
Author: ph10
Date: 2011-09-19 13:28:24 +0100 (Mon, 19 Sep 2011)
Log Message:
-----------
Fix minimum length bug with *ACCEPT.
Modified Paths:
--------------
code/trunk/ChangeLog
code/trunk/configure.ac
code/trunk/pcre_study.c
code/trunk/testdata/testinput2
code/trunk/testdata/testoutput2
Modified: code/trunk/ChangeLog
===================================================================
--- code/trunk/ChangeLog 2011-09-18 15:09:49 UTC (rev 696)
+++ code/trunk/ChangeLog 2011-09-19 12:28:24 UTC (rev 697)
@@ -41,6 +41,13 @@
(*PRUNE) or any other control that caused it to give a non-standard return,
invalid errors such as "Error -26 (nested recursion at the same subject
position)" or even infinite loops could occur.
+
+7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
+ computing the minimum length on reaching *ACCEPT, and so ended up with the
+ wrong value of 1 rather than 0. Further investigation indicates that
+ computing a minimum subject length in the presence of *ACCEPT is difficult
+ (think back references, subroutine calls), and so I have changed the code so
+ that no minimum is registered for a pattern that contains *ACCEPT.
Version 8.13 16-Aug-2011
Modified: code/trunk/configure.ac
===================================================================
--- code/trunk/configure.ac 2011-09-18 15:09:49 UTC (rev 696)
+++ code/trunk/configure.ac 2011-09-19 12:28:24 UTC (rev 697)
@@ -10,8 +10,8 @@
m4_define(pcre_major, [8])
m4_define(pcre_minor, [20])
-m4_define(pcre_prerelease, [-RC1])
-m4_define(pcre_date, [2011-09-12])
+m4_define(pcre_prerelease, [-RC2])
+m4_define(pcre_date, [2011-09-18])
# Libtool shared library interface versions (current:revision:age)
m4_define(libpcre_version, [0:1:0])
Modified: code/trunk/pcre_study.c
===================================================================
--- code/trunk/pcre_study.c 2011-09-18 15:09:49 UTC (rev 696)
+++ code/trunk/pcre_study.c 2011-09-19 12:28:24 UTC (rev 697)
@@ -66,21 +66,20 @@
rather than bytes.
Arguments:
- code pointer to start of group (the bracket)
- startcode pointer to start of the whole pattern
- options the compiling options
- had_accept pointer to flag for (*ACCEPT) encountered
- int RECURSE depth
+ code pointer to start of group (the bracket)
+ startcode pointer to start of the whole pattern
+ options the compiling options
+ int RECURSE depth
Returns: the minimum length
- -1 if \C was encountered
+ -1 if \C in UTF-8 mode or (*ACCEPT) was encountered
-2 internal error (missing capturing bracket)
-3 internal error (opcode not listed)
*/
static int
find_minlength(const uschar *code, const uschar *startcode, int options,
- BOOL *had_accept_ptr, int recurse_depth)
+ int recurse_depth)
{
int length = -1;
BOOL utf8 = (options & PCRE_UTF8) != 0;
@@ -128,24 +127,25 @@
case OP_BRAPOS:
case OP_SBRAPOS:
case OP_ONCE:
- d = find_minlength(cc, startcode, options, had_accept_ptr, recurse_depth);
+ d = find_minlength(cc, startcode, options, recurse_depth);
if (d < 0) return d;
branchlength += d;
- if (*had_accept_ptr) return branchlength;
do cc += GET(cc, 1); while (*cc == OP_ALT);
cc += 1 + LINK_SIZE;
break;
- /* Reached end of a branch; if it's a ket it is the end of a nested
- call. If it's ALT it is an alternation in a nested call. If it is END it's
- the end of the outer call. All can be handled by the same code. If it is
- ACCEPT, it is essentially the same as END, but we set a flag so that
- counting stops. */
+ /* ACCEPT makes things far too complicated; we have to give up. */
case OP_ACCEPT:
case OP_ASSERT_ACCEPT:
- *had_accept_ptr = TRUE;
- /* Fall through */
+ return -1;
+
+ /* Reached end of a branch; if it's a ket it is the end of a nested
+ call. If it's ALT it is an alternation in a nested call. If it is END it's
+ the end of the outer call. All can be handled by the same code. If an
+ ACCEPT was previously encountered, use the length that was in force at that
+ time, and pass back the shortest ACCEPT length. */
+
case OP_ALT:
case OP_KET:
case OP_KETRMAX:
@@ -379,9 +379,7 @@
}
else
{
- d = find_minlength(cs, startcode, options, had_accept_ptr,
- recurse_depth);
- *had_accept_ptr = FALSE;
+ d = find_minlength(cs, startcode, options, recurse_depth);
}
}
else d = 0;
@@ -430,9 +428,7 @@
had_recurse = TRUE;
else
{
- branchlength += find_minlength(cs, startcode, options, had_accept_ptr,
- recurse_depth + 1);
- *had_accept_ptr = FALSE;
+ branchlength += find_minlength(cs, startcode, options, recurse_depth + 1);
}
cc += 1 + LINK_SIZE;
break;
@@ -1228,7 +1224,6 @@
{
int min;
BOOL bits_set = FALSE;
-BOOL had_accept = FALSE;
uschar start_bits[32];
pcre_extra *extra = NULL;
pcre_study_data *study;
@@ -1290,13 +1285,13 @@
/* Find the minimum length of subject string. */
-switch(min = find_minlength(code, code, re->options, &had_accept, 0))
+switch(min = find_minlength(code, code, re->options, 0))
{
case -2: *errorptr = "internal error: missing capturing bracket"; return NULL;
case -3: *errorptr = "internal error: opcode not recognized"; return NULL;
default: break;
}
-
+
/* If a set of starting bytes has been identified, or if the minimum length is
greater than zero, or if JIT optimization has been requested, get a pcre_extra
block and a pcre_study_data block. The study data is put in the latter, which
@@ -1336,10 +1331,14 @@
/* Always set the minlength value in the block, because the JIT compiler
makes use of it. However, don't set the bit unless the length is greater than
zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time
- checking this case. */
+ checking the zero case. */
- study->minlength = min;
- if (min > 0) study->flags |= PCRE_STUDY_MINLEN;
+ if (min > 0)
+ {
+ study->flags |= PCRE_STUDY_MINLEN;
+ study->minlength = min;
+ }
+ else study->minlength = 0;
/* If JIT support was compiled and requested, attempt the JIT compilation.
If no starting bytes were found, and the minimum length is zero, and JIT
Modified: code/trunk/testdata/testinput2
===================================================================
--- code/trunk/testdata/testinput2 2011-09-18 15:09:49 UTC (rev 696)
+++ code/trunk/testdata/testinput2 2011-09-19 12:28:24 UTC (rev 697)
@@ -3848,4 +3848,15 @@
/\btype\b\W*?\btext\b\W*?\bjavascript\b|\burl\b\W*?\bshell:|<input\b.*?\btype\b\W*?\bimage\b|\bonkeyup\b\W*?\=/IS
+/a(*SKIP)c|b(*ACCEPT)|/+SI
+ a
+
+/a(*SKIP)c|b(*ACCEPT)cd(*ACCEPT)|x/SI
+ ax
+
+'a*(*ACCEPT)b'+
+ \N\N
+ abc\N\N
+ bbb\N\N
+
/-- End of testinput2 --/
Modified: code/trunk/testdata/testoutput2
===================================================================
--- code/trunk/testdata/testoutput2 2011-09-18 15:09:49 UTC (rev 696)
+++ code/trunk/testdata/testoutput2 2011-09-19 12:28:24 UTC (rev 697)
@@ -12251,4 +12251,34 @@
Subject length lower bound = 8
Starting byte set: < o t u
+/a(*SKIP)c|b(*ACCEPT)|/+SI
+Capturing subpattern count = 0
+No options
+No first char
+No need char
+Study returned NULL
+ a
+ 0:
+ 0+
+
+/a(*SKIP)c|b(*ACCEPT)cd(*ACCEPT)|x/SI
+Capturing subpattern count = 0
+No options
+No first char
+No need char
+Subject length lower bound = -1
+Starting byte set: a b x
+ ax
+ 0: x
+
+'a*(*ACCEPT)b'+
+ \N\N
+No match
+ abc\N\N
+ 0: a
+ 0+ bc
+ bbb\N\N
+ 0:
+ 0+ bb
+
/-- End of testinput2 --/
