Hi,

When comint-read-input-ring reads history to the ring, the global
value of comint-input-ring-size (i.e. 500) is used regardless of the
local value due to the use of temp buffer. For example:

1. HISTSIZE=10 emacs -Q
2. M-x shell

The buffer-local value of comint-input-ring-size is correctly set to
10, but C-c C-l shows 500 commands.

The attached patch fixes the problem that comint-read-input-ring
ignores the buffer-local comint-input-ring-size. Thanks.