Fix buffer overflow in partial match test for CRLF in empty buffer.

ChangeLog

@@ -198,6 +198,9 @@ pcre2test for testing it.
 
 29. Fix small memory leak in pcre2test.
 
+30. Fix out-of-bounds read for partial matching of /./ against an empty string 
+when the newline type is CRLF.
+
 
 Version 10.22 29-July-2016
 --------------------------

src/pcre2_match.c

@@ -2379,7 +2379,7 @@ for (;;)
     case OP_ANY:
     if (IS_NEWLINE(eptr)) RRETURN(MATCH_NOMATCH);
     if (mb->partial != 0 &&
-        eptr + 1 >= mb->end_subject &&
+        eptr == mb->end_subject - 1 &&
         NLBLOCK->nltype == NLTYPE_FIXED &&
         NLBLOCK->nllen == 2 &&
         UCHAR21TEST(eptr) == NLBLOCK->nl[0])

testdata/testinput2

@@ -4922,4 +4922,7 @@ a)"xI
 
 %(*:(:(svvvvvvvvvv:]*[   Z!*;[]*[^[]*!^[+.+{{2,7}'      _\\\\\\\\\\\\\)?.:..    *w////\\\Q\\\\\\\\\\\\\\\T\\\\\+/?/////'+\\\EEE?/////'+/*+/[^K]?]//(w)%never_backslash_c,alt_verbnames,auto_callout
 
+/./newline=crlf
+\=ph
+
 # End of testinput2 

testdata/testoutput2

@@ -15374,6 +15374,10 @@ Failed: error 109 at offset 6: quantifier does not follow a repeatable item
 
 %(*:(:(svvvvvvvvvv:]*[   Z!*;[]*[^[]*!^[+.+{{2,7}'      _\\\\\\\\\\\\\)?.:..    *w////\\\Q\\\\\\\\\\\\\\\T\\\\\+/?/////'+\\\EEE?/////'+/*+/[^K]?]//(w)%never_backslash_c,alt_verbnames,auto_callout
 
+/./newline=crlf
+\=ph
+No match
+
 # End of testinput2 
 Error -63: PCRE2_ERROR_BADDATA (unknown error number)
 Error -62: bad serialized data