MDEV-4243 [PATCH] Warnings/errors while compiling with clang

fix the code to compile with clang. fix warnings too.

include/probes_mysql_nodtrace.h:
  clang++ doesn't like numeric _constants_ being used in ||
  (it suspects that the intention was | ). Boolean constants are ok.
sql/hostname.cc:
  only used in DBUG_ASSERT
sql/item.cc:
  str_to_time and str_to_datetime return bool, not MYSQL_TIMESTAMP_xxx
sql/item_func.cc:
  str_to_datetime_with_warn() returns bool, not MYSQL_TIMESTAMP_xxx
storage/cassandra/CMakeLists.txt:
  CMAKE_CXX_FLAGS can be empty
storage/connect/odbconn.cpp:
  HWND is void*
storage/connect/user_connect.h:
  deprecated on FreeBSD and unused anyway
storage/connect/value.cpp:
  bad characters inside. unused.
storage/spider/spd_trx.cc:
  clang++ warns that memset will also overwrite vtbl. it might be as well a good idea,
  as it asserts that the object will only be used as a storage.
  silence the warning.

1 files changed, 2 insertions, 3 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 248b0899026..38f5ed6bf5c 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -585,12 +585,11 @@ uint Item::temporal_precision(enum_field_types type)
     MYSQL_TIME_STATUS status;
     DBUG_ASSERT(fixed);
     if ((tmp= val_str(&buf)) &&
-        (type == MYSQL_TYPE_TIME ?
+        !(type == MYSQL_TYPE_TIME ?
          str_to_time(tmp->charset(), tmp->ptr(), tmp->length(),
                      &ltime, TIME_TIME_ONLY, &status) :
          str_to_datetime(tmp->charset(), tmp->ptr(), tmp->length(),
-                         &ltime, TIME_FUZZY_DATES, &status)) >
-        MYSQL_TIMESTAMP_ERROR)
+                         &ltime, TIME_FUZZY_DATES, &status)))
       return MY_MIN(status.precision, TIME_SECOND_PART_DIGITS);
   }
   return MY_MIN(decimals, TIME_SECOND_PART_DIGITS);