A fix and test case for Bug#6096 "field.max_length is always zero for

numeric columns (stmt_resultset_metadata)"


libmysql/libmysql.c:
  A fix for Bug#6096 "field.max_length is always zero for numeric columns
   (stmt_resultset_metadata)": set field->max_lenght for numeric
  columns when we set up skip_result functions. A minor drawback for this 
  approach is that field->max_length  can be not zero even if 
  STMT_ATTR_UPDATE_MAX_LENGTH is not set.
sql-common/my_time.c:
  Fix valgrind warning.
tests/client_test.c:
  A test case for Bug#6096 "field.max_length is always zero for numeric 
  columns (stmt_resultset_metadata)

libmysql/libmysql.c

@@ -1752,6 +1752,7 @@ static void stmt_update_metadata(MYSQL_STMT *stmt, MYSQL_ROWS *data);
 */
 #define MAX_DATETIME_REP_LENGTH 12
 
+#define MAX_DOUBLE_STRING_REP_LENGTH 331
 
 /**************** Misc utility functions ****************************/
 
@@ -3265,7 +3266,12 @@ static void read_binary_time(MYSQL_TIME *tm, uchar **pos)
     tm->second= (uint) to[7];
     tm->second_part= (length > 8) ? (ulong) sint4korr(to+8) : 0;
     tm->year= tm->month= 0;
-
+    if (tm->day)
+    {
+      /* Convert days to hours at once */
+      tm->hour+= tm->day*24;
+      tm->day= 0;
+    }
     *pos+= length;
   }
   else
@@ -3558,7 +3564,7 @@ static void fetch_float_with_conversion(MYSQL_BIND *param, MYSQL_FIELD *field,
       floating point -> string conversion nicely, honor all typecodes
       and param->offset possibly set in mysql_stmt_fetch_column
     */
-    char buff[331];
+    char buff[MAX_DOUBLE_STRING_REP_LENGTH];
     char *end;
     /* TODO: move this to a header shared between client and server. */
 #define NOT_FIXED_DEC  31
@@ -3992,32 +3998,43 @@ my_bool STDCALL mysql_stmt_bind_result(MYSQL_STMT *stmt, MYSQL_BIND *bind)
     switch (field->type) {
     case MYSQL_TYPE_NULL: /* for dummy binds */
       param->pack_length= 0;
+      field->max_length= 0;
       break;
     case MYSQL_TYPE_TINY:
       param->pack_length= 1;
+      field->max_length= 4;                     /* as in '-127' */
       break;
     case MYSQL_TYPE_YEAR:
     case MYSQL_TYPE_SHORT:
       param->pack_length= 2;
+      field->max_length= 6;                     /* as in '-32767' */
       break;
     case MYSQL_TYPE_INT24:
+      field->max_length= 9;  /* as in '16777216' or in '-8388607' */
+      param->pack_length= 4;
+      break;
     case MYSQL_TYPE_LONG:
+      field->max_length= 11;                    /* '-2147483647' */
       param->pack_length= 4;
       break;
     case MYSQL_TYPE_LONGLONG:
+      field->max_length= 21;                    /* '18446744073709551616' */
       param->pack_length= 8;
       break;
     case MYSQL_TYPE_FLOAT:
       param->pack_length= 4;
+      field->max_length= MAX_DOUBLE_STRING_REP_LENGTH;
       break;
     case MYSQL_TYPE_DOUBLE:
       param->pack_length= 8;
+      field->max_length= MAX_DOUBLE_STRING_REP_LENGTH;
       break;
     case MYSQL_TYPE_TIME:
     case MYSQL_TYPE_DATE:
     case MYSQL_TYPE_DATETIME:
     case MYSQL_TYPE_TIMESTAMP:
       param->skip_result= skip_result_with_length;
+      field->max_length= MAX_DATE_STRING_REP_LENGTH;
       break;
     case MYSQL_TYPE_DECIMAL:
     case MYSQL_TYPE_ENUM:

sql-common/my_time.c

@@ -743,9 +743,6 @@ void set_zero_time(MYSQL_TIME *tm)
 int my_time_to_str(const MYSQL_TIME *l_time, char *to)
 {
   uint extra_hours= 0;
-  /* Get extra hours, if we are getting data from the server */
-  if (l_time->year == 0 && l_time->month == 0)
-    extra_hours= l_time->day*24;
   return my_sprintf(to, (to, "%s%02d:%02d:%02d",
                          (l_time->neg ? "-" : ""),
                          extra_hours+ l_time->hour,

tests/client_test.c

@@ -10713,6 +10713,106 @@ static void test_bug6081()
   rc= simple_command(mysql, COM_CREATE_DB, current_db,
                      (ulong)strlen(current_db), 0);
   myquery_r(rc);
+  rc= mysql_select_db(mysql, current_db);
+  myquery(rc);
+}
+
+
+static void test_bug6096()
+{
+  MYSQL_STMT *stmt;
+  MYSQL_RES *query_result, *stmt_metadata;
+  const char *stmt_text;
+  MYSQL_BIND bind[12];
+  MYSQL_FIELD *query_field_list, *stmt_field_list;
+  ulong query_field_count, stmt_field_count;
+  int rc;
+  uint i;
+
+  myheader("test_bug6096");
+
+  stmt_text= "drop table if exists t1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+
+  stmt_text= "create table t1 (c_tinyint tinyint, c_smallint smallint, "
+                             " c_mediumint mediumint, c_int int, "
+                             " c_bigint bigint, c_float float, "
+                             " c_double double, c_varchar varchar(20), "
+                             " c_char char(20), c_time time, c_date date, "
+                             " c_datetime datetime)";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+  stmt_text= "insert into t1  values (-100, -20000, 30000000, 4, 8, 1.0, "
+                                     "2.0, 'abc', 'def', now(), now(), now())";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+
+  stmt_text= "select * from t1";
+
+  /* Run select in prepared and non-prepared mode and compare metadata */
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
+  query_result= mysql_store_result(mysql);
+  query_field_list= mysql_fetch_fields(query_result);
+  query_field_count= mysql_num_fields(query_result);
+
+  stmt= mysql_stmt_init(mysql);
+  rc= mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
+  check_execute(stmt, rc);
+  rc= mysql_stmt_execute(stmt);
+  check_execute(stmt, rc);
+  rc= 1;
+  mysql_stmt_attr_set(stmt, STMT_ATTR_UPDATE_MAX_LENGTH, (void*)&rc);
+  mysql_stmt_store_result(stmt);
+  stmt_metadata= mysql_stmt_result_metadata(stmt);
+  stmt_field_list= mysql_fetch_fields(stmt_metadata);
+  stmt_field_count= mysql_num_fields(stmt_metadata);
+  DIE_UNLESS(stmt_field_count == query_field_count);
+
+  /* Print out and check the metadata */
+
+  printf(" ---------------------------------------------------------------\n");
+  printf("             |                     Metadata \n");
+  printf(" ---------------------------------------------------------------\n");
+  printf("             |         Query          |   Prepared statement \n");
+  printf(" ---------------------------------------------------------------\n");
+  printf(" field name  |  length   | max_length |  length   |  max_length \n");
+  printf(" ---------------------------------------------------------------\n");
+
+  for (i= 0; i < query_field_count; ++i)
+  {
+    MYSQL_FIELD *f1= &query_field_list[i], *f2= &stmt_field_list[i];
+    printf(" %-11s | %9lu | %10lu | %9lu | %10lu \n",
+           f1->name, f1->length, f1->max_length, f2->length, f2->max_length);
+    DIE_UNLESS(f1->length == f2->length);
+  }
+  printf(" ---------------------------------------------------------------\n");
+
+  /* Bind and fetch the data */
+
+  bzero(bind, sizeof(bind));
+  for (i= 0; i < stmt_field_count; ++i)
+  {
+    bind[i].buffer_type= MYSQL_TYPE_STRING;
+    bind[i].buffer_length= stmt_field_list[i].max_length + 1;
+    bind[i].buffer= malloc(bind[i].buffer_length);
+  }
+  mysql_stmt_bind_result(stmt, bind);
+  rc= mysql_stmt_fetch(stmt);
+  check_execute(stmt, rc);
+  rc= mysql_stmt_fetch(stmt);
+  DIE_UNLESS(rc == MYSQL_NO_DATA);
+
+  /* Clean up */
+
+  for (i= 0; i < stmt_field_count; ++i)
+    free(bind[i].buffer);
+  mysql_stmt_close(stmt);
+  mysql_free_result(query_result);
+  stmt_text= "drop table t1";
+  rc= mysql_real_query(mysql, stmt_text, strlen(stmt_text));
+  myquery(rc);
 }
 
 
@@ -11031,6 +11131,7 @@ int main(int argc, char **argv)
     test_bug6059();         /* correct metadata for SELECT ... INTO OUTFILE */
     test_bug6046();         /* NATURAL JOIN transformation works in PS */
     test_bug6081();         /* test of mysql_create_db()/mysql_rm_db() */
+    test_bug6096();         /* max_length for numeric columns */
     /*
       XXX: PLEASE RUN THIS PROGRAM UNDER VALGRIND AND VERIFY THAT YOUR TEST
       DOESN'T CONTAIN WARNINGS/ERRORS BEFORE YOU PUSH.