Fix misbehaviour of pcre2_match() and pcre2_dfa_match() when PCRE2_FIRSTLINE was set for an anchored pattern.

Author: PhilipHazel

ChangeLog

@@ -142,6 +142,10 @@ above because \b and \B are defined in terms of \w.
 option, and (?aP) also sets (?aT) so that (?-aP) disables all ASCII
 restrictions on POSIX classes.
 
+37. If PCRE2_FIRSTLINE was set on an anchored pattern, pcre2_match() and 
+pcre2_dfa_match() misbehaved. PCRE2_FIRSTLINE is now ignored for anchored 
+patterns.
+
 
 Version 10.42 11-December-2022
 ------------------------------

doc/html/pcre2api.html

@@ -1686,7 +1686,7 @@ <h1>pcre2api man page</h1>
 PCRE2_USE_OFFSET_LIMIT, which provides a more general limiting facility. If
 PCRE2_FIRSTLINE is set with an offset limit, a match must occur in the first
 line and also within the offset limit. In other words, whichever limit comes
-first is used.
+first is used. This option has no effect for anchored patterns.
 <pre>
   PCRE2_LITERAL
 </pre>
@@ -2021,7 +2021,7 @@ <h1>pcre2api man page</h1>
 </pre>
 This option forces all the POSIX character classes, including [:digit:] and
 [:xdigit:], to match only ASCII characters, even when PCRE2_UCP is set. It can
-be changed within a pattern by means of the (?aP) option setting, but note that 
+be changed within a pattern by means of the (?aP) option setting, but note that
 this also sets PCRE2_EXTRA_ASCII_DIGIT in order to ensure that (?-aP) unsets
 all ASCII restrictions for POSIX classes.
 <pre>
@@ -4140,7 +4140,7 @@ <h1>pcre2api man page</h1>
 </P>
 <br><a name="SEC43" href="#TOC1">REVISION</a><br>
 <P>
-Last updated: 12 October 2023
+Last updated: 11 November 2023
 <br>
 Copyright &copy; 1997-2023 University of Cambridge.
 <br>

doc/pcre2.txt

@@ -1653,7 +1653,8 @@ COMPILING A PATTERN
        greater than 3. See also PCRE2_USE_OFFSET_LIMIT, which provides a  more
        general  limiting  facility.  If  PCRE2_FIRSTLINE is set with an offset
        limit, a match must occur in the first line and also within the  offset
-       limit. In other words, whichever limit comes first is used.
+       limit. In other words, whichever limit comes first is used. This option
+       has no effect for anchored patterns.
 
          PCRE2_LITERAL
 
@@ -3975,11 +3976,11 @@ AUTHOR
 
 REVISION
 
-       Last updated: 12 October 2023
+       Last updated: 11 November 2023
        Copyright (c) 1997-2023 University of Cambridge.
 
 
-PCRE2 10.43                     12 October 2023                    PCRE2API(3)
+PCRE2 10.43                    11 November 2023                    PCRE2API(3)
 ------------------------------------------------------------------------------
 
 

doc/pcre2api.3

@@ -1,4 +1,4 @@
-.TH PCRE2API 3 "12 October 2023" "PCRE2 10.43"
+.TH PCRE2API 3 "11 November 2023" "PCRE2 10.43"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .sp
@@ -1628,7 +1628,7 @@ PCRE2_FIRSTLINE if \fIstartoffset\fP is greater than 3. See also
 PCRE2_USE_OFFSET_LIMIT, which provides a more general limiting facility. If
 PCRE2_FIRSTLINE is set with an offset limit, a match must occur in the first
 line and also within the offset limit. In other words, whichever limit comes
-first is used.
+first is used. This option has no effect for anchored patterns.
 .sp
   PCRE2_LITERAL
 .sp
@@ -1979,7 +1979,7 @@ a pattern by means of the (?aT) option setting.
 .sp
 This option forces all the POSIX character classes, including [:digit:] and
 [:xdigit:], to match only ASCII characters, even when PCRE2_UCP is set. It can
-be changed within a pattern by means of the (?aP) option setting, but note that 
+be changed within a pattern by means of the (?aP) option setting, but note that
 this also sets PCRE2_EXTRA_ASCII_DIGIT in order to ensure that (?-aP) unsets
 all ASCII restrictions for POSIX classes.
 .sp
@@ -4148,6 +4148,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 12 October 2023
+Last updated: 11 November 2023
 Copyright (c) 1997-2023 University of Cambridge.
 .fi

doc/pcre2demo.3

@@ -1,4 +1,4 @@
-.TH PCRE2DEMO 3 "12 October 2023" "PCRE2 10.43-DEV"
+.TH PCRE2DEMO 3 "11 November 2023" "PCRE2 10.43-DEV"
 .\"AUTOMATICALLY GENERATED BY PrepareRelease - do not EDIT!
 .SH NAME
 // - A demonstration C program for PCRE2 - //

src/pcre2_dfa_match.c

@@ -3443,7 +3443,7 @@ anchored = (options & (PCRE2_ANCHORED|PCRE2_DFA_RESTART)) != 0 ||
 where to start. */
 
 startline = (re->flags & PCRE2_STARTLINE) != 0;
-firstline = (re->overall_options & PCRE2_FIRSTLINE) != 0;
+firstline = !anchored && (re->overall_options & PCRE2_FIRSTLINE) != 0;
 bumpalong_limit = end_subject;
 
 /* Initialize and set up the fixed fields in the callout block, with a pointer

src/pcre2_match.c

@@ -6836,7 +6836,7 @@ if (mcontext == NULL)
 else mb->memctl = mcontext->memctl;
 
 anchored = ((re->overall_options | options) & PCRE2_ANCHORED) != 0;
-firstline = (re->overall_options & PCRE2_FIRSTLINE) != 0;
+firstline = !anchored && (re->overall_options & PCRE2_FIRSTLINE) != 0;
 startline = (re->flags & PCRE2_STARTLINE) != 0;
 bumpalong_limit = (mcontext->offset_limit == PCRE2_UNSET)?
   true_end_subject : subject + mcontext->offset_limit;

testdata/testinput2

@@ -6028,4 +6028,17 @@ a)"xI
 
 # --------
 
+/
+/anchored, firstline
+    \x0a
+
+/
+/anchored,firstline,no_start_optimize
+    \x0a
+
+/
+/firstline
+    \x0a
+    abc\x0adef
+
 # End of testinput2

testdata/testinput6

@@ -5026,4 +5026,17 @@
 /c*+/
     ab\=ph,offset=2
 
+/
+/anchored, firstline
+    \x0a
+
+/
+/anchored,firstline,no_start_optimize
+    \x0a
+
+/
+/firstline
+    \x0a
+    abc\x0adef
+
 # End of testinput6

testdata/testoutput2

@@ -17901,6 +17901,23 @@ No match
 
 # --------
 
+/
+/anchored, firstline
+    \x0a
+ 0: \x0a
+
+/
+/anchored,firstline,no_start_optimize
+    \x0a
+ 0: \x0a
+
+/
+/firstline
+    \x0a
+ 0: \x0a
+    abc\x0adef
+ 0: \x0a
+
 # End of testinput2
 Error -70: PCRE2_ERROR_BADDATA (unknown error number)
 Error -62: bad serialized data