A fix and test case for Bug#6049 "Loss of sign when using prepared

statements and negative time/date values". 
The bug was in wrong sprintf format used in the client library.
The fix moves TIME -> string conversion functions to sql-common and
utilized them in the client library.


include/my_time.h:
  Declarations for new functions shared between the client and server.
libmysql/libmysql.c:
  Fix for Bug#6049 "Loss of sign when using prepared statements and negative
  time/date values": use the same function as the server to convert
  date/time/datetime values to strings.
sql-common/my_time.c:
  Implementation of my_{time,datetime,date,TIME}_to_str: it's
  needed by the client library, so it should be shared.
sql/field.cc:
  Don't create String object if it's not needed.
sql/item.cc:
  Don't create String object if it's not needed: TIME_to_string was
  moved to my_TIME_to_str, with different arguments.
sql/item_timefunc.cc:
  Don't create String object if it's not needed.
sql/mysql_priv.h:
  TIME_to_string and MAX_DATE_REP_LENGTH moved to the client library.
  MAX_DATE_REP_LENGTH was renamed to MAX_DATE_STRING_REP_LENGTH to not 
  conflict with the same name in libmysql.c
sql/protocol.cc:
  Don't create String object if it's not needed.
sql/time.cc:
  Implementation of my_{time,date,datetime,TIME}_to_str moved to my_time.c
  shared between the client and the server.
tests/client_test.c:
  A test case for Bug#6049.

1 files changed, 72 insertions, 0 deletions

diff --git a/sql-common/my_time.c b/sql-common/my_time.c
index 4b5daf53bea..93549f7340c 100644
--- a/sql-common/my_time.c
+++ b/sql-common/my_time.c
@@ -726,3 +726,75 @@ void set_zero_time(MYSQL_TIME *tm)
   tm->time_type= MYSQL_TIMESTAMP_NONE;
 }
 
+
+/*
+  Functions to convert time/date/datetime value to a string,
+  using default format.
+  This functions don't check that given TIME structure members are
+  in valid range. If they are not, return value won't reflect any
+  valid date either. Additionally, make_time doesn't take into
+  account time->day member: it's assumed that days have been converted
+  to hours already.
+
+  RETURN
+    number of characters written to 'to'
+*/
+
+int my_time_to_str(const MYSQL_TIME *l_time, char *to)
+{
+  return my_sprintf(to, (to, "%s%02d:%02d:%02d",
+                         (l_time->neg ? "-" : ""),
+                         l_time->hour,
+                         l_time->minute,
+                         l_time->second));
+}
+
+int my_date_to_str(const MYSQL_TIME *l_time, char *to)
+{
+  return my_sprintf(to, (to, "%04d-%02d-%02d",
+                         l_time->year,
+                         l_time->month,
+                         l_time->day));
+}
+
+int my_datetime_to_str(const MYSQL_TIME *l_time, char *to)
+{
+  return my_sprintf(to, (to, "%04d-%02d-%02d %02d:%02d:%02d",
+                         l_time->year,
+                         l_time->month,
+                         l_time->day,
+                         l_time->hour,
+                         l_time->minute,
+                         l_time->second));
+}
+
+
+/*
+  Convert struct DATE/TIME/DATETIME value to string using built-in
+  MySQL time conversion formats.
+
+  SYNOPSIS
+    my_TIME_to_string()
+
+  NOTE
+    The string must have at least MAX_DATE_STRING_REP_LENGTH bytes reserved.
+*/
+
+int my_TIME_to_str(const MYSQL_TIME *l_time, char *to)
+{
+  switch (l_time->time_type) {
+  case MYSQL_TIMESTAMP_DATETIME:
+    return my_datetime_to_str(l_time, to);
+  case MYSQL_TIMESTAMP_DATE:
+    return my_date_to_str(l_time, to);
+  case MYSQL_TIMESTAMP_TIME:
+    return my_time_to_str(l_time, to);
+  case MYSQL_TIMESTAMP_NONE:
+  case MYSQL_TIMESTAMP_ERROR:
+    to[0]='\0';
+    return 0;
+  default:
+    DBUG_ASSERT(0);
+    return 0;
+  }
+}