A cleanup for MDEV-17317 Add THD* parameter into Item::get_date() and stricter data type control to "fuzzydate"

Fixing C++ function check_date() to get the "fuzzydate" as
date_mode_t rather than ulonglong, so conversion from
date_time_t to ulonglong is now done inside C++ check_date(),
and no conversion is needed in the callers' code.

As an additional safety, modified the code not to pass
TIME_FUZZY_DATE to the low level C functions:
- check_date()
- str_to_datetime()
- str_to_time()
- number_to_datetime()
because TIME_FUZZY_DATE is known only on the C++ level,
C functions do not know it.

Soon we'll be adding more flags into the C++ level (i.e. to date_time_t),
e.g. for rounding. It's a good idea to prevent passing C++ specific
flags into pure C routines before this change.

Asserts were added into the affected C functions to verify
that the caller passed only known C level flags.

sql-common/my_time.c

@@ -58,6 +58,20 @@ uint calc_days_in_year(uint year)
           366 : 365);
 }
 
+
+#ifndef DBUG_OFF
+
+static const ulonglong C_KNOWN_FLAGS= C_TIME_NO_ZERO_IN_DATE |
+                                      C_TIME_NO_ZERO_DATE    |
+                                      C_TIME_INVALID_DATES   |
+                                      C_TIME_TIME_ONLY       |
+                                      C_TIME_DATETIME_ONLY;
+
+#define C_FLAGS_OK(flags)             (((flags) & ~C_KNOWN_FLAGS) == 0)
+
+#endif
+
+
 /**
   @brief Check datetime value for validity according to flags.
 
@@ -82,6 +96,7 @@ uint calc_days_in_year(uint year)
 my_bool check_date(const MYSQL_TIME *ltime, my_bool not_zero_date,
                    ulonglong flags, int *was_cut)
 {
+  DBUG_ASSERT(C_FLAGS_OK(flags));
   if (ltime->time_type == MYSQL_TIMESTAMP_TIME)
     return FALSE;
   if (not_zero_date)
@@ -298,6 +313,7 @@ str_to_datetime(const char *str, size_t length, MYSQL_TIME *l_time,
   const char *end=str+length, *pos;
   uint number_of_fields= 0, digits, year_length, not_zero_date;
   DBUG_ENTER("str_to_datetime");
+  DBUG_ASSERT(C_FLAGS_OK(flags));
   bzero(l_time, sizeof(*l_time));
 
   if (flags & C_TIME_TIME_ONLY)
@@ -464,6 +480,7 @@ my_bool str_to_time(const char *str, size_t length, MYSQL_TIME *l_time,
   const char *end=str+length, *end_of_days;
   my_bool found_days,found_hours, neg= 0;
   uint UNINIT_VAR(state);
+  DBUG_ASSERT(C_FLAGS_OK(fuzzydate));
 
   my_time_status_init(status);
   for (; str != end && my_isspace(&my_charset_latin1,*str) ; str++)
@@ -1209,6 +1226,7 @@ longlong number_to_datetime(longlong nr, ulong sec_part, MYSQL_TIME *time_res,
                             ulonglong flags, int *was_cut)
 {
   long part1,part2;
+  DBUG_ASSERT(C_FLAGS_OK(flags));
 
   *was_cut= 0;
   time_res->time_type=MYSQL_TIMESTAMP_DATE;

sql/item_timefunc.cc

@@ -441,7 +441,7 @@ static bool extract_date_time(THD *thd, DATE_TIME_FORMAT *format,
     goto err;
 
   int was_cut;
-  if (check_date(l_time, ulonglong(fuzzydate | TIME_INVALID_DATES), &was_cut))
+  if (check_date(l_time, fuzzydate | TIME_INVALID_DATES, &was_cut))
     goto err;
 
   if (val != val_end)

sql/sql_basic_types.h

@@ -98,5 +98,11 @@ const date_mode_t
   TIME_NO_ZERO_DATE           (date_mode_t::value_t::NO_ZERO_DATE),
   TIME_INVALID_DATES          (date_mode_t::value_t::INVALID_DATES);
 
+// Flags understood by str_to_datetime, str_to_time, number_to_time, check_date
+static const date_mode_t
+  TIME_MODE_FOR_XXX_TO_DATE   (date_mode_t::NO_ZERO_IN_DATE |
+                               date_mode_t::NO_ZERO_DATE    |
+                               date_mode_t::INVALID_DATES   |
+                               date_mode_t::TIME_ONLY);
 
 #endif

sql/sql_time.cc

@@ -293,7 +293,7 @@ check_date_with_warn(THD *thd, const MYSQL_TIME *ltime, date_mode_t fuzzydate,
                      timestamp_type ts_type)
 {
   int unused;
-  if (check_date(ltime, ulonglong(fuzzydate), &unused))
+  if (check_date(ltime, fuzzydate, &unused))
   {
     ErrConvTime str(ltime);
     make_truncated_value_warning(thd, Sql_condition::WARN_LEVEL_WARN,
@@ -377,7 +377,9 @@ 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, ulonglong(fuzzydate), status);
+  return ::str_to_time(tmp.str, tmp.length, this,
+                       ulonglong(fuzzydate & TIME_MODE_FOR_XXX_TO_DATE),
+                       status);
 }
 
 
@@ -387,7 +389,9 @@ 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, ulonglong(flags), status);
+  return ::str_to_datetime(tmp.str, tmp.length, this,
+                           ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE),
+                           status);
 }
 
 
@@ -407,7 +411,8 @@ str_to_datetime_with_warn(THD *thd, CHARSET_INFO *cs,
   MYSQL_TIME_STATUS status;
   TemporalAsciiBuffer tmp(str, length, cs);
   bool ret_val= str_to_datetime(tmp.str, tmp.length, l_time,
-                                ulonglong(flags), &status);
+                                ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE),
+                                &status);
   if (ret_val || status.warnings)
   {
     const ErrConvString err(str, length, &my_charset_bin);
@@ -1339,7 +1344,7 @@ time_to_datetime_with_warn(THD *thd,
   */
   if (time_to_datetime(thd, from, to) ||
       ((thd->variables.old_behavior & OLD_MODE_ZERO_DATE_TIME_CAST) &&
-        check_date(to, ulonglong(fuzzydate), &warn)))
+        check_date(to, fuzzydate, &warn)))
   {
     ErrConvTime str(from);
     thd->push_warning_truncated_wrong_value("datetime", str.ptr());

sql/sql_time.h

@@ -167,9 +167,10 @@ non_zero_date(const MYSQL_TIME *ltime)
           non_zero_hhmmssuu(ltime));
 }
 static inline bool
-check_date(const MYSQL_TIME *ltime, ulonglong flags, int *was_cut)
+check_date(const MYSQL_TIME *ltime, date_mode_t flags, int *was_cut)
 {
- return check_date(ltime, non_zero_date(ltime), flags, was_cut);
+ return check_date(ltime, non_zero_date(ltime),
+                   ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE), was_cut);
 }
 bool check_date_with_warn(THD *thd, const MYSQL_TIME *ltime, date_mode_t fuzzy_date,
                           timestamp_type ts_type);

sql/sql_type.cc

@@ -480,7 +480,8 @@ void Temporal_with_date::make_from_item(THD *thd, Item *item)
 
 void Temporal_with_date::check_date_or_invalidate(int *warn, date_mode_t flags)
 {
-  if (check_date(this, pack_time(this) != 0, ulonglong(flags), warn))
+  if (check_date(this, pack_time(this) != 0,
+                 ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE), warn))
     time_type= MYSQL_TIMESTAMP_NONE;
 }
 

sql/sql_type.h

@@ -285,7 +285,9 @@ public:
       *warn= MYSQL_TIME_WARN_OUT_OF_RANGE;
       return true;
     }
-    return number_to_datetime(m_sec, m_usec, to, ulonglong(flags), warn) == -1;
+    return number_to_datetime(m_sec, m_usec, to,
+                              ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE),
+                              warn) == -1;
   }
   // Convert elapsed seconds to TIME
   bool sec_to_time(MYSQL_TIME *ltime, uint dec) const
@@ -1230,7 +1232,9 @@ public:
   bool check_date(date_mode_t flags, int *warnings) const
   {
     DBUG_ASSERT(is_valid_datetime_slow());
-    return ::check_date(this, (year || month || day), ulonglong(flags), warnings);
+    return ::check_date(this, (year || month || day),
+                        ulonglong(flags & TIME_MODE_FOR_XXX_TO_DATE),
+                        warnings);
   }
   bool check_date(date_mode_t flags) const
   {