Fixed error found during review of new pushed code

client/mysql.cc:
  Don't use c_ptr() for cgets() and ensure buffer is not overwritten
mysql-test/r/cast.result:
  More test for CAST(0x.... as signed)
sql/opt_sum.cc:
  Fix bugs found during review
  - Changed code to be able to remove one if
  - Ensure that count == 0 only if is_exact_count == TRUE
sql/sql_delete.cc:
  Ensure 'allow_sum_func' is reset before call to setup_conds
sql/sql_lex.cc:
  allow_sum_func doesn't have to be reset for each query
  (It's to be reset in setup_fields() or before call to setup_conds()
sql/sql_load.cc:
  Move set of auto_increment_field_not_null so that it's not set if field value is NULL
sql/sql_prepare.cc:
  allow_sum_func doesn't have to be reset for each query
  (It's to be reset in setup_fields() or before call to setup_conds()
sql/sql_update.cc:
  Ensure 'allow_sum_func' is reset before call to setup_conds

client/mysql.cc

@@ -993,13 +993,13 @@ static int read_lines(bool execute_commands)
       unsigned long clen;
       do
       {
-        line= my_cgets(tmpbuf.c_ptr(), tmpbuf.alloced_length(), &clen);
+        line= my_cgets(tmpbuf.ptr(), tmpbuf.alloced_length()-1, &clen);
         buffer.append(line, clen);
         /* 
            if we got buffer fully filled than there is a chance that
            something else is still in console input buffer
         */
-      } while (tmpbuf.alloced_length() <= clen + 1);
+      } while (tmpbuf.alloced_length() <= clen);
       line= buffer.c_ptr();
 #else /* OS2 */
       buffer.length(0);

mysql-test/r/cast.result

@@ -54,6 +54,18 @@ CONVERT(DATE "2004-01-22 21:45:33",BINARY(4))
 select CAST(DATE "2004-01-22 21:45:33" AS BINARY(4));
 CAST(DATE "2004-01-22 21:45:33" AS BINARY(4))
 2004
+select CAST(0xb3 as signed);
+CAST(0xb3 as signed)
+179
+select CAST(0x8fffffffffffffff as signed);
+CAST(0x8fffffffffffffff as signed)
+-8070450532247928833
+select CAST(0xffffffffffffffff as unsigned);
+CAST(0xffffffffffffffff as unsigned)
+18446744073709551615
+select CAST(0xfffffffffffffffe as signed);
+CAST(0xfffffffffffffffe as signed)
+-2
 select cast('18446744073709551616' as unsigned);
 cast('18446744073709551616' as unsigned)
 18446744073709551615

sql/opt_sum.cc

@@ -108,7 +108,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
           WHERE t2.field IS NULL;
       */
       if (tl->table->map & where_tables)
-        const_result= 0;
+        return 0;
     }
     else
       used_tables|= tl->table->map;
@@ -119,7 +119,10 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
       may be used as the real count.
     */
     if (tl->table->file->table_flags() & HA_NOT_EXACT_COUNT)
+    {
       is_exact_count= FALSE;
+      count= 1;                                 // ensure count != 0
+    }
     else
     {
       tl->table->file->info(HA_STATUS_VARIABLE | HA_STATUS_NO_LOCK);
@@ -127,9 +130,6 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
     }
   }
 
-  if (!const_result)
-    return 0;
-
   /*
     Iterate through all items in the SELECT clause and replace
     COUNT(), MIN() and MAX() with constants (if possible).
@@ -150,8 +150,8 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
         if (!conds && !((Item_sum_count*) item)->args[0]->maybe_null &&
             !outer_tables && is_exact_count)
         {
-            ((Item_sum_count*) item)->make_const(count);
-            recalc_const_item= 1;
+          ((Item_sum_count*) item)->make_const(count);
+          recalc_const_item= 1;
         }
         else
           const_result= 0;
@@ -234,7 +234,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
         }
         if (!count)
         {
-          /* If count != 1, then we know that is_exact_count == TRUE. */
+          /* If count == 0, then we know that is_exact_count == TRUE. */
           ((Item_sum_min*) item_sum)->clear(); /* Set to NULL. */
         }
         else

sql/sql_delete.cc

@@ -27,8 +27,8 @@
 #include "ha_innodb.h"
 #include "sql_select.h"
 
-int mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds, SQL_LIST *order,
-                 ha_rows limit, ulong options)
+int mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
+                 SQL_LIST *order, ha_rows limit, ulong options)
 {
   int		error;
   TABLE		*table;
@@ -266,6 +266,7 @@ int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
 				  select_lex.table_list.first);
   DBUG_ENTER("mysql_prepare_delete");
 
+  thd->allow_sum_func= 0;
   if (setup_conds(thd, delete_table_list, conds) || 
       setup_ftfuncs(&thd->lex->select_lex))
     DBUG_RETURN(-1);

sql/sql_lex.cc

@@ -160,7 +160,6 @@ void lex_start(THD *thd, uchar *buf,uint length)
   lex->duplicates= DUP_ERROR;
   lex->ignore= 0;
   lex->proc_list.first= 0;
-  thd->allow_sum_func= 0;
 }
 
 void lex_end(LEX *lex)

sql/sql_load.cc

@@ -429,8 +429,6 @@ read_fixed_length(THD *thd,COPY_INFO &info,TABLE *table,List<Item> &fields,
     while ((sql_field= (Item_field*) it++))
     {
       Field *field= sql_field->field;                  
-      if (field == table->next_number_field)
-        table->auto_increment_field_not_null= TRUE;
       if (pos == read_info.row_end)
       {
         thd->cuted_fields++;			/* Not enough fields */
@@ -443,11 +441,13 @@ read_fixed_length(THD *thd,COPY_INFO &info,TABLE *table,List<Item> &fields,
       {
 	uint length;
 	byte save_chr;
+        if (field == table->next_number_field)
+          table->auto_increment_field_not_null= TRUE;
 	if ((length=(uint) (read_info.row_end-pos)) >
 	    field->field_length)
 	  length=field->field_length;
 	save_chr=pos[length]; pos[length]='\0'; // Safeguard aganst malloc
-  field->store((char*) pos,length,read_info.read_charset);
+        field->store((char*) pos,length,read_info.read_charset);
 	pos[length]=save_chr;
 	if ((pos+=length) > read_info.row_end)
 	  pos= read_info.row_end;	/* Fills rest with space */
@@ -522,8 +522,6 @@ read_sep_field(THD *thd,COPY_INFO &info,TABLE *table,
       length=(uint) (read_info.row_end-pos);
       Field *field=sql_field->field;
 
-      if (field == table->next_number_field)
-        table->auto_increment_field_not_null= TRUE;
       if (!read_info.enclosed &&
 	  (enclosed_length && length == 4 && !memcmp(pos,"NULL",4)) ||
 	  (length == 1 && read_info.found_null))
@@ -540,6 +538,8 @@ read_sep_field(THD *thd,COPY_INFO &info,TABLE *table,
 	}
 	continue;
       }
+      if (field == table->next_number_field)
+        table->auto_increment_field_not_null= TRUE;
       field->set_notnull();
       read_info.row_end[0]=0;			// Safe to change end marker
       field->store((char*) read_info.row_start,length,read_info.read_charset);

sql/sql_prepare.cc

@@ -1738,7 +1738,6 @@ static void reset_stmt_for_execute(Prepared_statement *stmt)
   lex->current_select= &lex->select_lex;
   if (lex->result)
     lex->result->cleanup();
-  thd->allow_sum_func= 0;
 }
 
 

sql/sql_update.cc

@@ -426,6 +426,7 @@ int mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
   bzero((char*) &tables,sizeof(tables));	// For ORDER BY
   tables.table= table;
   tables.alias= table_list->alias;
+  thd->allow_sum_func= 0;
 
   if (setup_tables(update_table_list) ||
       setup_conds(thd, update_table_list, conds) ||