MDEV-17563 Different results using table or view when comparing values of time type

MDEV-17625 Different warnings when comparing a garbage to DATETIME vs TIME

- Splitting processes of data type conversion (to TIME/DATE,DATETIME)
  and warning generation.
  Warning are now only get collected during conversion (in an "int" variable),
  and are pushed in the very end of conversion (not in parallel).
  Warnings generated by the low level routines str_to_xxx() and number_to_xxx()
  can now be changed at the end, when TIME_FUZZY_DATES is applied,
  from "Invalid value" to "Truncated invalid value".

  Now "Illegal value" is issued only when the low level routine returned
  an error and TIME_FUZZY_DATES was not set. Otherwise, if the low level
  routine returned "false" (success), or if NULL was converted to a zero
  datetime by TIME_FUZZY_DATES, then "Truncated illegal value"
  is issued. This gives better warnings.

- Methods Type_handler::Item_get_date() and
  Type_handler::Item_func_hybrid_field_type_get_date() now only
  convert and collect warning information, but do not push warnings.

- Changing the return data type for Type_handler::Item_get_date()
  and Type_handler::Item_func_hybrid_field_type_get_date() from
  "bool" to "void". The conversion result (success vs error) can be
  checked by testing ltime->time_type. MYSQL_TIME_{NONE|ERROR}
  mean mean error, other values mean success.

- Adding new wrapper methods Type_handler::Item_get_date_with_warn() and
  Type_handler::Item_func_hybrid_field_type_get_date_with_warn()
  to do conversion followed by raising warnings, and changing
  the code to call new Type_handler::***_with_warn() methods.

- Adding a helper class Temporal::Status, a wrapper
  for MYSQL_TIME_STATUS with automatic initialization.

- Adding a helper class Temporal::Warn, to collect warnings
  but without actually raising them. Moving a part of ErrConv
  into a separate class ErrBuff, and deriving both Temporal::Warn
  and ErrConv from ErrBuff. The ErrBuff part of Temporal::Warn
  is used to collect textual representation of the input data.

- Adding a helper class Temporal::Warn_push. It's used
  to collect warning information during conversion, and
  automatically pushes warnings to the diagnostics area
  on its destructor time (in case of non-zero warning).

- Moving more code from various functions inside class Temporal.

- Adding more Temporal_hybrid constructors and
  protected Temporal methods make_from_xxx(),
  which convert and only collect warning information, but do not
  actually raise warnings.

- Now the low level functions  str_to_datetime() and str_to_time()
  always set status->warning if the return value is "true" (error).

- Now the low level functions number_to_time() and number_to_datetime()
  set the "*was_cut" argument if the return value is "true" (error).

- Adding a few DBUG_ASSERTs to make sure that str_to_xxx() and
  number_to_xxx() always set warnings on error.

- Adding new warning flags MYSQL_TIME_WARN_EDOM and MYSQL_TIME_WARN_ZERO_DATE
  for the code symmetry. Before this change there was a special
  code path for (rc==true && was_cut==0) which was treated by
  Field_temporal::store_invalid_with_warning as "zero date violation".
  Now was_cut==0 always means that there are no any error/warnings/notes
  to be raised, not matter what rc is.

- Using new Temporal_hybrid constructors in combination with
  Temporal::Warn_push inside str_to_datetime_with_warn(),
  double_to_datetime_with_warn(), int_to_datetime_with_warn(),
  Field::get_date(), Item::get_date_from_string(), and a few other places.

- Removing methods Dec_ptr::to_datetime_with_warn(),
  Year::to_time_with_warn(), my_decimal::to_datetime_with_warn(),
  Dec_ptr::to_datetime_with_warn().
  Fixing Sec6::to_time() and Sec6::to_datetime() to
  convert and only collect warnings, without raising warnings.
  Now warning raising functionality resides in Temporal::Warn_push.

- Adding classes Longlong_hybrid_null and Double_null, to
  return both value and the "IS NULL" flag. Adding methods
  Item::to_double_null(), to_longlong_hybrid_null(),
  Item_func_hybrid_field_type::to_longlong_hybrid_null_op(),
  Item_func_hybrid_field_type::to_double_null_op().
  Removing separate classes VInt and VInt_op, as they
  have been replaced by a single class Longlong_hybrid_null.

- Adding a helper method Temporal::type_name_by_timestamp_type(),
  moving a part of make_truncated_value_warning() into it,
  and reusing in Temporal::Warn::push_conversion_warnings().

- Removing Item::make_zero_date() and
  Item_func_hybrid_field_type::make_zero_mysql_time().
  They provided duplicate functionality.
  Now this code resides in Temporal::make_fuzzy_date().
  The latter is now called for all Item types when data type
  conversion (to DATE/TIME/DATETIME) is involved, including
  Item_field and Item_direct_view_ref.
  This fixes MDEV-17563: Item_direct_view_ref now correctly converts
  NULL to a zero date when TIME_FUZZY_DATES says so.

1 files changed, 21 insertions, 62 deletions

diff --git a/sql/sql_time.cc b/sql/sql_time.cc
index 630d150be77..9562394f11e 100644
--- a/sql/sql_time.cc
+++ b/sql/sql_time.cc
@@ -377,9 +377,11 @@ bool Temporal::str_to_time(MYSQL_TIME_STATUS *status,
                            date_mode_t fuzzydate)
 {
   TemporalAsciiBuffer tmp(str, length, cs);
-  return ::str_to_time(tmp.str, tmp.length, this,
+  bool rc= ::str_to_time(tmp.str, tmp.length, this,
                        ulonglong(fuzzydate & TIME_MODE_FOR_XXX_TO_DATE),
                        status);
+  DBUG_ASSERT(status->warnings || !rc);
+  return rc;
 }
 
 
@@ -389,9 +391,11 @@ bool Temporal::str_to_datetime(MYSQL_TIME_STATUS *status,
                                date_mode_t flags)
 {
   TemporalAsciiBuffer tmp(str, length, cs);
-  return ::str_to_datetime(tmp.str, tmp.length, this,
+  bool rc= ::str_to_datetime(tmp.str, tmp.length, this,
                            ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE),
                            status);
+  DBUG_ASSERT(status->warnings || !rc);
+  return rc;
 }
 
 
@@ -401,7 +405,9 @@ bool Interval_DDhhmmssff::str_to_DDhhmmssff(MYSQL_TIME_STATUS *status,
                                             CHARSET_INFO *cs, ulong max_hour)
 {
   TemporalAsciiBuffer tmp(str, length, cs);
-  return ::str_to_DDhhmmssff(tmp.str, tmp.length, this, UINT_MAX32, status);
+  bool rc= ::str_to_DDhhmmssff(tmp.str, tmp.length, this, UINT_MAX32, status);
+  DBUG_ASSERT(status->warnings || !rc);
+  return rc;
 }
 
 
@@ -413,45 +419,22 @@ bool Interval_DDhhmmssff::str_to_DDhhmmssff(MYSQL_TIME_STATUS *status,
     See description of str_to_datetime() for more information.
 */
 
-static bool
-str_to_datetime_with_warn(THD *thd, CHARSET_INFO *cs,
-                          const char *str, size_t length, MYSQL_TIME *l_time,
-                          date_mode_t flags, MYSQL_TIME_STATUS *status)
-{
-  Temporal_hybrid *t= new(l_time) Temporal_hybrid(status, str, length, cs, flags);
-  if (!t->is_valid_temporal() || status->warnings)
-  {
-    const ErrConvString err(str, length, &my_charset_bin);
-    make_truncated_value_warning(thd,
-                                 !t->is_valid_temporal() ?
-                                 Sql_condition::WARN_LEVEL_WARN :
-                                 Sql_condition::time_warn_level(status->warnings),
-                                 &err, flags & TIME_TIME_ONLY ?
-                                 MYSQL_TIMESTAMP_TIME : l_time->time_type, NullS);
-  }
-  DBUG_EXECUTE_IF("str_to_datetime_warn",
-                  push_warning(thd, Sql_condition::WARN_LEVEL_NOTE,
-                               ER_YES, str););
-  return !t->is_valid_temporal();
-}
-
-
 bool
 str_to_datetime_with_warn(THD *thd, CHARSET_INFO *cs,
-                          const char *str, size_t length, MYSQL_TIME *l_time,
-                          date_mode_t flags)
+                          const char *str, size_t length, MYSQL_TIME *to,
+                          date_mode_t mode)
 {
-  MYSQL_TIME_STATUS status;
-  return str_to_datetime_with_warn(thd, cs, str, length, l_time, flags, &status);
+  Temporal::Warn_push warn(thd, NullS, to, mode);
+  Temporal_hybrid *t= new(to) Temporal_hybrid(thd, &warn, str, length, cs, mode);
+  return !t->is_valid_temporal();
 }
 
 
 bool double_to_datetime_with_warn(THD *thd, double value, MYSQL_TIME *ltime,
                                   date_mode_t fuzzydate, const char *field_name)
 {
-  const ErrConvDouble str(value);
-  Temporal_hybrid *t= new (ltime) Temporal_hybrid(thd, Sec6(value), fuzzydate,
-                                                  &str, field_name);
+  Temporal::Warn_push warn(thd, field_name, ltime, fuzzydate);
+  Temporal_hybrid *t= new (ltime) Temporal_hybrid(thd, &warn, value, fuzzydate);
   return !t->is_valid_temporal();
 }
 
@@ -460,9 +443,8 @@ bool decimal_to_datetime_with_warn(THD *thd, const my_decimal *value,
                                    MYSQL_TIME *ltime,
                                    date_mode_t fuzzydate, const char *field_name)
 {
-  const ErrConvDecimal str(value);
-  Temporal_hybrid *t= new (ltime) Temporal_hybrid(thd, Sec6(value), fuzzydate,
-                                                  &str, field_name);
+  Temporal::Warn_push warn(thd, field_name, ltime, fuzzydate);
+  Temporal_hybrid *t= new (ltime) Temporal_hybrid(thd, &warn, value, fuzzydate);
   return !t->is_valid_temporal();
 }
 
@@ -471,14 +453,12 @@ bool int_to_datetime_with_warn(THD *thd, const Longlong_hybrid &nr,
                                MYSQL_TIME *ltime,
                                date_mode_t fuzzydate, const char *field_name)
 {
-  const ErrConvInteger str(nr);
   /*
     Note: conversion from an integer to TIME can overflow to '838:59:59.999999',
     so the conversion result can have fractional digits.
   */
-  Temporal_hybrid *t= new (ltime)
-                      Temporal_hybrid(thd, Sec6(nr),
-                                      fuzzydate, &str, field_name);
+  Temporal::Warn_push warn(thd, field_name, ltime, fuzzydate);
+  Temporal_hybrid *t= new (ltime) Temporal_hybrid(thd, &warn, nr, fuzzydate);
   return !t->is_valid_temporal();
 }
 
@@ -909,20 +889,7 @@ void make_truncated_value_warning(THD *thd,
 				  timestamp_type time_type,
                                   const char *field_name)
 {
-  const char *type_str;
-
-  switch (time_type) {
-    case MYSQL_TIMESTAMP_DATE: 
-      type_str= "date";
-      break;
-    case MYSQL_TIMESTAMP_TIME:
-      type_str= "time";
-      break;
-    case MYSQL_TIMESTAMP_DATETIME:  // FALLTHROUGH
-    default:
-      type_str= "datetime";
-      break;
-  }
+  const char *type_str= Temporal::type_name_by_timestamp_type(time_type);
   return thd->push_warning_wrong_or_truncated_value(level,
                                            time_type <= MYSQL_TIMESTAMP_ERROR,
                                            type_str, sval->ptr(), field_name);
@@ -1400,11 +1367,3 @@ void unpack_time(longlong packed, MYSQL_TIME *my_time,
     break;
   }
 }
-
-
-bool my_decimal::to_datetime_with_warn(THD *thd, MYSQL_TIME *to,
-                                       date_mode_t fuzzydate,
-                                       const char *field_name)
-{
-  return decimal_to_datetime_with_warn(thd, this, to, fuzzydate, field_name);
-}