Add options for NULL pointers to pcre2test.

ChangeLog

@@ -28,6 +28,8 @@ from pcre2grep.
 9. Merged patch from @carenas (GitHub #53) fixing NULL checks in matching and 
 substituting.
 
+10. Add null_subject and null_replacement modifiers to pcre2test.
+
 
 Version 10.39 29-October-2021
 -----------------------------

doc/html/pcre2api.html

@@ -3655,7 +3655,9 @@ default.
 </P>
 <P>
 PCRE2_ERROR_NULL is returned if PCRE2_SUBSTITUTE_MATCHED is set but the
-<i>match_data</i> argument is NULL.
+<i>match_data</i> argument is NULL or if the <i>subject</i> or <i>replacement</i>
+arguments are NULL. For backward compatibility reasons an exception is made for
+the <i>replacement</i> argument if the <i>rlength</i> argument is also 0.
 </P>
 <P>
 PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax errors in the

doc/html/pcre2test.html

@@ -1239,6 +1239,8 @@ pattern, but can be overridden by modifiers on the subject.
       match_limit=<n>            set a match limit
       memory                     show heap memory usage
       null_context               match with a NULL context
+      null_replacement           substitute with NULL replacement
+      null_subject               match with NULL subject  
       offset=<n>                 set starting offset
       offset_limit=<n>           set offset limit
       ovector=<n>                set size of output vector
@@ -1668,7 +1670,7 @@ When testing <b>pcre2_substitute()</b>, this modifier also has the effect of
 passing the replacement string as zero-terminated.
 </P>
 <br><b>
-Passing a NULL context
+Passing a NULL context, subject, or replacement
 </b><br>
 <P>
 Normally, <b>pcre2test</b> passes a context block to <b>pcre2_match()</b>,
@@ -1678,6 +1680,11 @@ testing that the matching and substitution functions behave correctly in this
 case (they use default values). This modifier cannot be used with the
 <b>find_limits</b> or <b>substitute_callout</b> modifiers.
 </P>
+<P>
+Similarly, for testing purposes, if the <b>null_subject</b> or 
+<b>null_replacement</b> modifier is set, the subject or replacement string 
+pointers are passed as NULL, respectively, to the relevant functions.
+</P>
 <br><a name="SEC12" href="#TOC1">THE ALTERNATIVE MATCHING FUNCTION</a><br>
 <P>
 By default, <b>pcre2test</b> uses the standard PCRE2 matching function,
@@ -2122,7 +2129,7 @@ Cambridge, England.
 </P>
 <br><a name="SEC21" href="#TOC1">REVISION</a><br>
 <P>
-Last updated: 30 August 2021
+Last updated: 28 November 2021
 <br>
 Copyright &copy; 1997-2021 University of Cambridge.
 <br>

doc/pcre2.txt

@@ -3524,7 +3524,9 @@ CREATING A NEW STRING WITH SUBSTITUTIONS
        does not happen by default.
 
        PCRE2_ERROR_NULL is returned if PCRE2_SUBSTITUTE_MATCHED is set but the
-       match_data argument is NULL.
+       match_data argument is NULL or if the subject or replacement  arguments
+       are  NULL.  For backward compatibility reasons an exception is made for
+       the replacement argument if the rlength argument is also 0.
 
        PCRE2_ERROR_BADREPLACEMENT is used for miscellaneous syntax  errors  in
        the  replacement  string,  with  more particular errors being PCRE2_ER-

doc/pcre2test.1

@@ -1,4 +1,4 @@
-.TH PCRE2TEST 1 "30 August 2021" "PCRE 10.38"
+.TH PCRE2TEST 1 "28 November 2021" "PCRE 10.40"
 .SH NAME
 pcre2test - a program for testing Perl-compatible regular expressions.
 .SH SYNOPSIS
@@ -1206,6 +1206,8 @@ pattern, but can be overridden by modifiers on the subject.
       match_limit=<n>            set a match limit
       memory                     show heap memory usage
       null_context               match with a NULL context
+      null_replacement           substitute with NULL replacement
+      null_subject               match with NULL subject  
       offset=<n>                 set starting offset
       offset_limit=<n>           set offset limit
       ovector=<n>                set size of output vector
@@ -1629,7 +1631,7 @@ When testing \fBpcre2_substitute()\fP, this modifier also has the effect of
 passing the replacement string as zero-terminated.
 .
 .
-.SS "Passing a NULL context"
+.SS "Passing a NULL context, subject, or replacement"
 .rs
 .sp
 Normally, \fBpcre2test\fP passes a context block to \fBpcre2_match()\fP,
@@ -1638,6 +1640,10 @@ If the \fBnull_context\fP modifier is set, however, NULL is passed. This is for
 testing that the matching and substitution functions behave correctly in this
 case (they use default values). This modifier cannot be used with the
 \fBfind_limits\fP or \fBsubstitute_callout\fP modifiers.
+.P
+Similarly, for testing purposes, if the \fBnull_subject\fP or 
+\fBnull_replacement\fP modifier is set, the subject or replacement string 
+pointers are passed as NULL, respectively, to the relevant functions.
 .
 .
 .SH "THE ALTERNATIVE MATCHING FUNCTION"
@@ -2103,6 +2109,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 30 August 2021
+Last updated: 28 November 2021
 Copyright (c) 1997-2021 University of Cambridge.
 .fi

doc/pcre2test.txt

@@ -1111,6 +1111,8 @@ SUBJECT MODIFIERS
              match_limit=<n>            set a match limit
              memory                     show heap memory usage
              null_context               match with a NULL context
+             null_replacement           substitute with NULL replacement
+             null_subject               match with NULL subject
              offset=<n>                 set starting offset
              offset_limit=<n>           set offset limit
              ovector=<n>                set size of output vector
@@ -1499,7 +1501,7 @@ SUBJECT MODIFIERS
        When testing pcre2_substitute(), this modifier also has the  effect  of
        passing the replacement string as zero-terminated.
 
-   Passing a NULL context
+   Passing a NULL context, subject, or replacement
 
        Normally,   pcre2test   passes   a   context  block  to  pcre2_match(),
        pcre2_dfa_match(), pcre2_jit_match()  or  pcre2_substitute().   If  the
@@ -1508,6 +1510,10 @@ SUBJECT MODIFIERS
        in  this  case  (they use default values). This modifier cannot be used
        with the find_limits or substitute_callout modifiers.
 
+       Similarly, for testing purposes, if the null_subject  or  null_replace-
+       ment  modifier  is  set, the subject or replacement string pointers are
+       passed as NULL, respectively, to the relevant functions.
+
 
 THE ALTERNATIVE MATCHING FUNCTION
 
@@ -1933,5 +1939,5 @@ AUTHOR
 
 REVISION
 
-       Last updated: 30 August 2021
+       Last updated: 28 November 2021
        Copyright (c) 1997-2021 University of Cambridge.

src/pcre2test.c

@@ -516,6 +516,8 @@ so many of them that they are split into two fields. */
 #define CTL2_CALLOUT_NO_WHERE            0x00000200u
 #define CTL2_CALLOUT_EXTRA               0x00000400u
 #define CTL2_ALLVECTOR                   0x00000800u
+#define CTL2_NULL_SUBJECT                0x00001000u
+#define CTL2_NULL_REPLACEMENT            0x00002000u
 
 #define CTL2_NL_SET                      0x40000000u  /* Informational */
 #define CTL2_BSR_SET                     0x80000000u  /* Informational */
@@ -706,6 +708,8 @@ static modstruct modlist[] = {
   { "notempty_atstart",            MOD_DAT,  MOD_OPT, PCRE2_NOTEMPTY_ATSTART,     DO(options) },
   { "noteol",                      MOD_DAT,  MOD_OPT, PCRE2_NOTEOL,               DO(options) },
   { "null_context",                MOD_PD,   MOD_CTL, CTL_NULLCONTEXT,            PO(control) },
+  { "null_replacement",            MOD_DAT,  MOD_CTL, CTL2_NULL_REPLACEMENT,      DO(control2) },
+  { "null_subject",                MOD_DAT,  MOD_CTL, CTL2_NULL_SUBJECT,          DO(control2) },
   { "offset",                      MOD_DAT,  MOD_INT, 0,                          DO(offset) },
   { "offset_limit",                MOD_CTM,  MOD_SIZ, 0,                          MO(offset_limit)},
   { "ovector",                     MOD_DAT,  MOD_INT, 0,                          DO(oveccount) },
@@ -7064,9 +7068,14 @@ pp = memmove(dbuffer + dbuffer_size - len - c, dbuffer, len + c);
   VALGRIND_MAKE_MEM_NOACCESS(dbuffer, dbuffer_size - (len + c));
 #endif
 
-/* Now pp points to the subject string. POSIX matching is only possible in
+/* Now pp points to the subject string, but if null_subject was specified, set
-8-bit mode, and it does not support timing or other fancy features. Some were
+it to NULL to test PCRE2's behaviour. */
-checked at compile time, but we need to check the match-time settings here. */
+
+if ((dat_datctl.control2 & CTL2_NULL_SUBJECT) != 0) pp = NULL;
+
+/* POSIX matching is only possible in 8-bit mode, and it does not support
+timing or other fancy features. Some were checked at compile time, but we need
+to check the match-time settings here. */
 
 #ifdef SUPPORT_PCRE2_8
 if ((pat_patctl.control & CTL_POSIX) != 0)
@@ -7293,6 +7302,7 @@ if (dat_datctl.replacement[0] != 0)
   uint8_t *pr;
   uint8_t rbuffer[REPLACE_BUFFSIZE];
   uint8_t nbuffer[REPLACE_BUFFSIZE];
+  uint8_t *rbptr; 
   uint32_t xoptions;
   uint32_t emoption;  /* External match option */
   PCRE2_SIZE j, rlen, nsize, erroroffset;
@@ -7443,9 +7453,14 @@ if (dat_datctl.replacement[0] != 0)
     PCRE2_SET_SUBSTITUTE_CALLOUT(dat_context, NULL, NULL);  /* No callout */
     }
     
+  /* There is a special option to set the replacement to NULL in order to test
+  that case. */
+  
+  rbptr = ((dat_datctl.control2 & CTL2_NULL_REPLACEMENT) == 0)? rbuffer : NULL;
+
   PCRE2_SUBSTITUTE(rc, compiled_code, pp, arg_ulen, dat_datctl.offset,
     dat_datctl.options|xoptions, match_data, use_dat_context,
-    rbuffer, rlen, nbuffer, &nsize);
+    rbptr, rlen, nbuffer, &nsize);
 
   if (rc < 0)
     {