Proposed fix for Bug#4026 "Microseconds part of TIME/DATETIME types

is broken (prepared statements)": fixed date handling in many places 
of prepared statements code.


libmysql/libmysql.c:
  Fix for Bug#4026:
  - now buffer_length is defined for any buffer type. Network buffer 
    preallocation cleaned up.
  - added constants for maximum buffer sizes necessary for MYSQL_TYPE_DATE,
    MYSQL_TYPE_TIME, MYSQL_TYPE_DATETIME types.
  - TIME/DATETIME packing/unpacking functions fixed 
  - now result set metadata is always updated from fields sent to COM_EXECUTE.
    This is necessary to make 'SELECT ?' queries work without conversions.
sql/item.cc:
  - added implementatoin of Item_param::get_date
sql/item.h:
  - added enum_field_types Item_param::param_type. First step for proper
    handling of placeholders.
  - added get_date() implementation to prevent date -> string -> date 
    conversions when MYSQL_TYPE_DATE/DATETIME parameter is used in temporal 
    context.
sql/protocol.cc:
  Fix for Bug#4026:
  - PACKET_BUFFET_EXTRA_ALLOC -> PACKET_BUFFER_EXTRA_ALLOC.
    The define itself was moved to .cc as it's used only in protocol.cc
  - fixed Protocol_prep::store_time() call.
sql/protocol.h:
  - PACKET_BUFFER_EXTRA_ALLOC moved to protocol.cc
sql/sql_prepare.cc:
  Fix for Bug#4026:
  - MYSQL_TYPE_TIME/DATETIME handling fixed.
  - added initialization for Item_param::param_type in 
    setup_one_conversion_function
tests/client_test.c:
  Test case for Bug#4026

1 files changed, 12 insertions, 14 deletions

diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index 1713c81a096..ab181e02735 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -332,20 +332,19 @@ static void set_param_time(Item_param *param, uchar **pos, ulong len)
   {
     uchar *to= *pos;
     TIME  tm;
-    
-    /* TODO: why length is compared with 8 here? */
-    tm.second_part= (length > 8 ) ? (ulong) sint4korr(to+7): 0;
 
+    tm.neg= (bool) to[0];
+    day= (uint) sint4korr(to+1);
     /*
       Note, that though ranges of hour, minute and second are not checked
       here we rely on them being < 256: otherwise
       we'll get buffer overflow in make_{date,time} functions,
       which are called when time value is converted to string.
     */
-    day= (uint) sint4korr(to+1);
     tm.hour=   (uint) to[5] + day * 24;
     tm.minute= (uint) to[6];
     tm.second= (uint) to[7];
+    tm.second_part= (length > 8) ? (ulong) sint4korr(to+8) : 0;
     if (tm.hour > 838)
     {
       /* TODO: add warning 'Data truncated' here */
@@ -354,7 +353,6 @@ static void set_param_time(Item_param *param, uchar **pos, ulong len)
       tm.second= 59;
     }
     tm.day= tm.year= tm.month= 0;
-    tm.neg= (bool)to[0];
 
     param->set_time(&tm, TIMESTAMP_TIME,
                     MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
@@ -365,14 +363,16 @@ static void set_param_time(Item_param *param, uchar **pos, ulong len)
 static void set_param_datetime(Item_param *param, uchar **pos, ulong len)
 {
   uint length;
- 
+
   if ((length= get_param_length(pos, len)) >= 4)
   {
     uchar *to= *pos;
     TIME  tm;
-    
-    tm.second_part= (length > 7 ) ? (ulong) sint4korr(to+7): 0;
-    
+
+    tm.neg=    0;
+    tm.year=   (uint) sint2korr(to);
+    tm.month=  (uint) to[2];
+    tm.day=    (uint) to[3];
     /*
       Note, that though ranges of hour, minute and second are not checked
       here we rely on them being < 256: otherwise
@@ -386,11 +386,8 @@ static void set_param_datetime(Item_param *param, uchar **pos, ulong len)
     }
     else
       tm.hour= tm.minute= tm.second= 0;
-    
-    tm.year=   (uint) sint2korr(to);
-    tm.month=  (uint) to[2];
-    tm.day=    (uint) to[3];
-    tm.neg=    0;
+
+    tm.second_part= (length > 7) ? (ulong) sint4korr(to+7) : 0;
 
     param->set_time(&tm, TIMESTAMP_DATETIME, 
                     MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN);
@@ -585,6 +582,7 @@ static void setup_one_conversion_function(THD *thd, Item_param *param,
       param->item_result_type= STRING_RESULT;
     }
   }
+  param->param_type= (enum enum_field_types) param_type;
 }
 
 #ifndef EMBEDDED_LIBRARY