MDEV-13173 An RLIKE that previously worked on 10.0 now returns "Got error 'pcre_exec: recursion limit of 100 exceeded' from regexp"

1. use Regexp_processor_pcre::set_recursion_limit() to set the
   recursion limit depending on the current available stack size
2. make pcre stack frame to be estimated no less than 500 bytes.
   sometimes pcre estimates it too low, even though the manual
   says 500+16 bytes (it was estimated only 188 for me, actual
   frame size was 512).
3. do it for embedded too

1 files changed, 2 insertions, 0 deletions

diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index 769bde67cb1..1b133d1d885 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -231,6 +231,7 @@ public:
     DBUG_VOID_RETURN;
   }
   String *val_str(String *str);
+  bool fix_fields(THD *thd, Item **ref);
   void fix_length_and_dec();
   const char *func_name() const { return "regexp_replace"; }
 };
@@ -251,6 +252,7 @@ public:
     DBUG_VOID_RETURN;
   }
   String *val_str(String *str);
+  bool fix_fields(THD *thd, Item **ref);
   void fix_length_and_dec();
   const char *func_name() const { return "regexp_substr"; }
 };