1 files changed, 13 insertions, 13 deletions

diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index 1ce8bad933b..d745dd8ff73 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -120,10 +120,11 @@ static int cmp_row_type(Item* item1, Item* item2)
 
 static int agg_cmp_type(Item_result *type, Item **items, uint nitems)
 {
-  uint i;
+  uint unsigned_count= items[0]->unsigned_flag;
   type[0]= items[0]->cmp_type();
-  for (i= 1 ; i < nitems ; i++)
+  for (uint i= 1 ; i < nitems ; i++)
   {
+    unsigned_count+= items[i]->unsigned_flag;
     type[0]= item_cmp_type(type[0], items[i]);
     /*
       When aggregating types of two row expressions we have to check
@@ -135,6 +136,12 @@ static int agg_cmp_type(Item_result *type, Item **items, uint nitems)
     if (type[0] == ROW_RESULT && cmp_row_type(items[0], items[i]))
       return 1;     // error found: invalid usage of rows
   }
+  /**
+    If all arguments are of INT type but have different unsigned_flag values,
+    switch to DECIMAL_RESULT.
+  */
+  if (type[0] == INT_RESULT && unsigned_count != nitems && unsigned_count != 0)
+    type[0]= DECIMAL_RESULT;
   return 0;
 }
 
@@ -2334,10 +2341,7 @@ bool Item_func_ifnull::date_op(MYSQL_TIME *ltime, uint fuzzydate)
   DBUG_ASSERT(fixed == 1);
   if (!args[0]->get_date_with_conversion(ltime, fuzzydate & ~TIME_FUZZY_DATES))
     return (null_value= false);
-  if (!args[1]->get_date_with_conversion(ltime, fuzzydate & ~TIME_FUZZY_DATES))
-    return (null_value= false);
-  bzero((char*) ltime,sizeof(*ltime));
-  return null_value= !(fuzzydate & TIME_FUZZY_DATES);
+  return (null_value= args[1]->get_date_with_conversion(ltime, fuzzydate & ~TIME_FUZZY_DATES));
 }
 
 
@@ -3367,16 +3371,12 @@ double Item_func_coalesce::real_op()
 bool Item_func_coalesce::date_op(MYSQL_TIME *ltime,uint fuzzydate)
 {
   DBUG_ASSERT(fixed == 1);
-  null_value= 0;
   for (uint i= 0; i < arg_count; i++)
   {
-    bool res= args[i]->get_date_with_conversion(ltime,
-                                                fuzzydate & ~TIME_FUZZY_DATES);
-    if (!args[i]->null_value)
-      return res;
+    if (!args[i]->get_date_with_conversion(ltime, fuzzydate & ~TIME_FUZZY_DATES))
+      return (null_value= false);
   }
-  bzero((char*) ltime,sizeof(*ltime));
-  return null_value|= !(fuzzydate & TIME_FUZZY_DATES);
+  return (null_value= true);
 }