Bug#31434 mysqldump dumps view as table

mysqldump creates stand-in tables before dumping the actual view.
Those tables were of the default type; if the view had more columns
than that (a pathological case, arguably), loading the dump would
fail. We now make the temporary stand-ins MyISAM tables to prevent
this.

client/mysqldump.c:
  When creating a stand-in table, specify its type to
  avoid defaulting to a type with a column-number limit
  (like Inno). The type is always MyISAM as we know that
  to be available.
mysql-test/r/mysqldump.result:
  mysqldump sets engine-type (MyISAM) for stand-in tables
  for views now. Update test results.

client/mysqldump.c

@@ -1836,7 +1836,13 @@ static uint get_table_structure(char *table, char *db, char *table_type,
               fprintf(sql_file, ",\n  %s %s",
                       quote_name(row[0], name_buff, 0), row[1]);
             }
-            fprintf(sql_file, "\n) */;\n");
+            /*
+              Stand-in tables are always MyISAM tables as the default
+              engine might have a column-limit that's lower than the
+              number of columns in the view, and MyISAM support is
+              guaranteed to be in the server anyway.
+            */
+            fprintf(sql_file, "\n) ENGINE=MyISAM */;\n");
             check_io(sql_file);
           }
         }