Make the test for over-complication while auto-possessifying bite sooner.

ChangeLog

@@ -272,6 +272,11 @@ to return PCRE2_ERROR_CALLOUT from a callout.
 41. A minor change to pcre2grep: colour reset is now "<esc>[0m" instead of 
 "<esc>[00m".
 
+42. The limit in the auto-possessification code that was intended to catch 
+overly-complicated patterns and not spend too much time auto-possessifying was 
+being reset too often, resulting in very long compile times for some patterns.
+Now such patterns are no longer completely auto-possessified.
+
 
 Version 10.22 29-July-2016
 --------------------------

src/pcre2_auto_possess.c

@@ -1046,8 +1046,10 @@ but some compilers complain about an unreachable statement. */
 
 /* Replaces single character iterations with their possessive alternatives
 if appropriate. This function modifies the compiled opcode! Hitting a
-non-existant opcode may indicate a bug in PCRE2, but it can also be caused if a
-bad UTF string was compiled with PCRE2_NO_UTF_CHECK.
+non-existent opcode may indicate a bug in PCRE2, but it can also be caused if a
+bad UTF string was compiled with PCRE2_NO_UTF_CHECK. The rec_limit catches 
+overly complicated or large patterns. In these cases, the check just stops, 
+leaving the remainder of the pattern unpossessified.
 
 Arguments:
   code        points to start of the byte code
@@ -1065,7 +1067,7 @@ PCRE2_UCHAR c;
 PCRE2_SPTR end;
 PCRE2_UCHAR *repeat_opcode;
 uint32_t list[8];
-int rec_limit;
+int rec_limit = 10000;
 
 for (;;)
   {
@@ -1080,7 +1082,6 @@ for (;;)
       get_chr_property_list(code, utf, cb->fcc, list) : NULL;
     list[1] = c == OP_STAR || c == OP_PLUS || c == OP_QUERY || c == OP_UPTO;
 
-    rec_limit = 1000;
     if (end != NULL && compare_opcodes(end, utf, cb, list, end, &rec_limit))
       {
       switch(c)
@@ -1137,7 +1138,6 @@ for (;;)
 
       list[1] = (c & 1) == 0;
 
-      rec_limit = 1000;
       if (compare_opcodes(end, utf, cb, list, end, &rec_limit))
         {
         switch (c)

testdata/testinput15

@@ -160,4 +160,9 @@
 /(*NO_AUTO_POSSESS)\w+(?C1)/BI
     abc\=callout_fail=1
 
+# This test breaks the JIT stack limit 
+
+/(|]+){2,2452}/
+    (|]+){2,2452}
+
 # End of testinput15

testdata/testoutput15

@@ -380,4 +380,11 @@ Subject length lower bound = 1
   1   ^^    
 No match
 
+# This test breaks the JIT stack limit 
+
+/(|]+){2,2452}/
+    (|]+){2,2452}
+ 0: 
+ 1: 
+
 # End of testinput15