MDEV-10524 Assertion `arg1_int >= 0' failed in Item_func_additive_op::result_precision()

This change is a backport from 10.0 to 5.5 for:
1. The full patch for:
     MDEV-4841 Wrong character set of ADDTIME() and DATE_ADD()
     9adb6e991ec87b65d04929f115d9d0c899e4ab19

2. A small fragment of:
     MDEV-5298 Illegal mix of collations on timestamp
     03f6778d61a74bdd7d09103a16473a2a5624cf66
   which overrides Item_temporal_hybrid_func::cmp_type(),
   and adds a new line into cache_temporal_4265.result.

1 files changed, 25 insertions, 4 deletions

diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index 28e93683422..420fb29f518 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -1455,25 +1455,29 @@ bool get_interval_value(Item *args,interval_type int_type, INTERVAL *interval)
 
 void Item_temporal_func::fix_length_and_dec()
 { 
+  uint char_length= mysql_temporal_int_part_length(field_type());
   /*
     We set maybe_null to 1 as default as any bad argument with date or
     time can get us to return NULL.
   */ 
   maybe_null= 1;
-  max_length= mysql_temporal_int_part_length(field_type());
+
   if (decimals)
   {
     if (decimals == NOT_FIXED_DEC)
-      max_length+= TIME_SECOND_PART_DIGITS + 1;
+      char_length+= TIME_SECOND_PART_DIGITS + 1;
     else
     {
       set_if_smaller(decimals, TIME_SECOND_PART_DIGITS);
-      max_length+= decimals + 1;
+      char_length+= decimals + 1;
     }
   }
   sql_mode= current_thd->variables.sql_mode &
                  (MODE_NO_ZERO_IN_DATE | MODE_NO_ZERO_DATE);
-  collation.set(&my_charset_numeric, DERIVATION_NUMERIC, MY_REPERTOIRE_ASCII);
+  collation.set(field_type() == MYSQL_TYPE_STRING ?
+                default_charset() : &my_charset_numeric,
+                DERIVATION_NUMERIC, MY_REPERTOIRE_ASCII);
+  fix_char_length(char_length);
 }
 
 String *Item_temporal_func::val_str(String *str)
@@ -1483,6 +1487,23 @@ String *Item_temporal_func::val_str(String *str)
 }
 
 
+String *Item_temporal_hybrid_func::val_str_ascii(String *str)
+{
+  DBUG_ASSERT(fixed == 1);
+  MYSQL_TIME ltime;
+
+  if (get_date(&ltime, 0) ||
+      (null_value= my_TIME_to_str(&ltime, str, decimals)))
+    return (String *) 0;
+
+  /* Check that the returned timestamp type matches to the function type */
+  DBUG_ASSERT(cached_field_type == MYSQL_TYPE_STRING ||
+              ltime.time_type == MYSQL_TIMESTAMP_NONE ||
+              mysql_type_to_time_type(cached_field_type) == ltime.time_type);
+  return str;
+}
+
+
 bool Item_func_from_days::get_date(MYSQL_TIME *ltime, ulonglong fuzzy_date)
 {
   longlong value=args[0]->val_int();