Fix data overrun for /(?(?C)/

ChangeLog

@@ -8,6 +8,10 @@ Version 10.20 xx-xx-2015
 
 2. Assertion code generator in JIT has been optimized.
 
+3. The invalid pattern (?(?C) has a missing assertion condition at the end. The
+pcre2_compile() function read past the end of the input before diagnosing an
+error.
+
 
 Version 10.10 06-March-2015
 ---------------------------

src/pcre2_compile.c

@@ -5252,6 +5252,15 @@ for (;; ptr++)
                 }
               }
             }
+
+          /* tempptr should now be pointing to the opening parenthesis of the
+          assertion condition. */
+
+          if (*tempptr != CHAR_LEFT_PARENTHESIS)
+            {
+            *errorcodeptr = ERR28;
+            goto FAILED;
+            }
           }
 
         /* For conditions that are assertions, check the syntax, and then exit

src/pcre2_error.c

@@ -97,7 +97,7 @@ static const char compile_error_texts[] =
   "lookbehind assertion is not fixed length\0"
   "malformed number or name after (?(\0"
   "conditional group contains more than two branches\0"
-  "assertion expected after (?(\0"
+  "assertion expected after (?( or (?(?C)\0"
   "(?R or (?[+-]digits must be followed by )\0"
   /* 30 */
   "unknown POSIX class name\0"

src/pcre2posix.c

@@ -216,8 +216,8 @@ if ((cflags & REG_UTF) != 0)      options |= PCRE2_UTF;
 if ((cflags & REG_UCP) != 0)      options |= PCRE2_UCP;
 if ((cflags & REG_UNGREEDY) != 0) options |= PCRE2_UNGREEDY;
 
-preg->re_pcre2_code = pcre2_compile((PCRE2_SPTR)pattern, -1, options,
-  &errorcode, &erroffset, NULL);
+preg->re_pcre2_code = pcre2_compile((PCRE2_SPTR)pattern, PCRE2_ZERO_TERMINATED,
+   options, &errorcode, &erroffset, NULL);
 preg->re_erroffset = erroffset;
 
 if (preg->re_pcre2_code == NULL)

testdata/testinput17

@@ -90,4 +90,6 @@
 
 /abc/\
 
+"(?(?C)"
+
 # End of testdata/testinput16  

testdata/testoutput17

@@ -142,4 +142,7 @@ No match: POSIX code 17: match failed
 /abc/\
 Failed: POSIX code 9: bad escape sequence at offset 4     
 
+"(?(?C)"
+Failed: POSIX code 3: pattern error at offset 2     
+
 # End of testdata/testinput16  

testdata/testoutput2

@@ -567,7 +567,7 @@ Failed: error 126 at offset 4: malformed number or name after (?(
 Failed: error 126 at offset 4: malformed number or name after (?(
 
 /(?(?i))/
-Failed: error 128 at offset 3: assertion expected after (?(
+Failed: error 128 at offset 3: assertion expected after (?( or (?(?C)
 
 /(?(abc))/
 Failed: error 115 at offset 7: reference to non-existent subpattern
@@ -7367,7 +7367,7 @@ No match
 Failed: error 126 at offset 6: malformed number or name after (?(
 
 /(?(''))/
-Failed: error 128 at offset 4: assertion expected after (?(
+Failed: error 128 at offset 4: assertion expected after (?( or (?(?C)
 
 /(?('R')stuff)/
 Failed: error 115 at offset 7: reference to non-existent subpattern