Make pcre2test give an error for \P, \p, and \X after #forbid_utf.

ChangeLog

@@ -134,6 +134,9 @@ provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
 
 34. Give an error for an empty subpattern name such as (?'').
 
+35. Make pcre2test give an error if a pattern that follows #forbud_utf contains 
+\P, \p, or \X.
+
 
 Version 10.10 06-March-2015
 ---------------------------

doc/pcre2test.1

@@ -1,4 +1,4 @@
-.TH PCRE2TEST 1 "22 April 2015" "PCRE 10.20"
+.TH PCRE2TEST 1 "20 May 2015" "PCRE 10.20"
 .SH NAME
 pcre2test - a program for testing Perl-compatible regular expressions.
 .SH SYNOPSIS
@@ -237,13 +237,19 @@ following commands are recognized:
   #forbid_utf
 .sp
 Subsequent patterns automatically have the PCRE2_NEVER_UTF and PCRE2_NEVER_UCP
-options set, which locks out the use of UTF and Unicode property features. This
+options set, which locks out the use of the PCRE2_UTF and PCRE2_UCP options and 
-is a trigger guard that is used in test files to ensure that UTF or Unicode
+the use of (*UTF) and (*UCP) at the start of patterns. This command also forces
-property tests are not accidentally added to files that are used when Unicode
+an error if a subsequent pattern contains any occurrences of \eP, \ep, or \eX,
-support is not included in the library. This effect can also be obtained by the
+which are still supported when PCRE2_UTF is not set, but which require Unicode
-use of \fB#pattern\fP; the difference is that \fB#forbid_utf\fP cannot be
+property support to be included in the library.
-unset, and the automatic options are not displayed in pattern information, to
+.P
-avoid cluttering up test output.
+This is a trigger guard that is used in test files to ensure that UTF or
+Unicode property tests are not accidentally added to files that are used when
+Unicode support is not included in the library. Setting PCRE2_NEVER_UTF and 
+PCRE2_NEVER_UCP as a default can also be obtained by the use of \fB#pattern\fP;
+the difference is that \fB#forbid_utf\fP cannot be unset, and the automatic
+options are not displayed in pattern information, to avoid cluttering up test
+output.
 .sp
   #load <filename>
 .sp
@@ -1445,6 +1451,6 @@ Cambridge, England.
 .rs
 .sp
 .nf
-Last updated: 22 April 2015
+Last updated: 20 May 2015
 Copyright (c) 1997-2015 University of Cambridge.
 .fi

src/pcre2_compile.c

@@ -1729,8 +1729,12 @@ else if (c < ESCAPES_FIRST || c > ESCAPES_LAST) {}  /* Definitely literal */
 
 else if ((i = escapes[c - ESCAPES_FIRST]) != 0)
   {
-  if (i > 0) c = (uint32_t)i;   /* Positive is a data character */
+  if (i > 0) c = (uint32_t)i; else  /* Positive is a data character */
-    else escape = -i;           /* Else return a special escape */
+    {
+    escape = -i;                    /* Else return a special escape */
+    if (escape == ESC_P || escape == ESC_p || escape == ESC_X)
+      cb->external_flags |= PCRE2_HASBKPORX;   /* Note \P, \p, or \X */  
+    } 
   }
 
 /* Escapes that need further processing, including those that are unknown. */

src/pcre2_internal.h

@@ -525,6 +525,7 @@ bytes in a code unit in that mode. */
 #define PCRE2_NE_ATST_SET   0x00020000  /* (*NOTEMPTY_ATSTART) used) together */
 #define PCRE2_DEREF_TABLES  0x00040000  /* Release character tables. */
 #define PCRE2_NOJIT         0x00080000  /* (*NOJIT) used */
+#define PCRE2_HASBKPORX     0x00100000  /* contains \P, \p, or \X */
 
 #define PCRE2_MODE_MASK     (PCRE2_MODE8 | PCRE2_MODE16 | PCRE2_MODE32)
 

src/pcre2test.c

@@ -4492,6 +4492,20 @@ if (TEST(compiled_code, ==, NULL))
   fprintf(outfile, "\n");
   return PR_SKIP;
   }
+  
+/* If forbid_utf is non-zero, we are running a non-UTF test. UTF and UCP are 
+locked out at compile time, but we must also check for occurrences of \P, \p, 
+and \X, which are only supported when Unicode is supported. */
+
+if (forbid_utf != 0)
+  {
+  if ((FLD(compiled_code, flags) & PCRE2_HASBKPORX) != 0)
+    {
+    fprintf(outfile, "** \\P, \\p, and \\X are not allowed after the "
+      "#forbid_utf command\n");
+    return PR_SKIP;     
+    }     
+  }  
 
 /* Remember the maximum lookbehind, for partial matching. */