A fix (bug #2205 USE database doesn't work after DROP database + CREATE database)

(Jani's CS 1.1675 04/01/05 21:45:14 was adapted an aplied).

client/mysql.cc

@@ -2200,8 +2200,9 @@ static int com_source(String *buffer, char *line)
 static int
 com_use(String *buffer __attribute__((unused)), char *line)
 {
-  char *tmp;
-  char buff[256];
+  char *tmp, buff[FN_REFLEN + 1];
+  MYSQL_RES *res;
+  MYSQL_ROW row;
 
   while (isspace(*line))
     line++;
@@ -2214,6 +2215,30 @@ com_use(String *buffer __attribute__((unused)), char *line)
     put_info("USE must be followed by a database name",INFO_ERROR);
     return 0;
   }
+  /*
+    We need to recheck the current database, because it may change
+    under our feet, for example if DROP DATABASE or RENAME DATABASE
+    (latter one not yet available by the time the comment was written)
+  */
+  current_db= 0; // Let's reset current_db, assume it's gone
+  /*
+    We don't care about in case of an error below because current_db
+    was just set to 0.
+  */
+  if (!mysql_query(&mysql, "SELECT DATABASE()") &&
+      (res= mysql_use_result(&mysql)))
+  {
+    row= mysql_fetch_row(res);
+    if (row[0] &&
+        (!current_db || cmp_database(current_db, row[0])))
+    {
+      my_free(current_db, MYF(MY_ALLOW_ZERO_PTR));
+      current_db= my_strdup(row[0], MYF(MY_WME));
+    }
+    (void) mysql_fetch_row(res);               // Read eof
+    mysql_free_result(res);
+  }
+
   if (!current_db || cmp_database(current_db,tmp))
   {
     if (one_database)