Fix coding systems used for X input methods

* doc/emacs/mule.texi (International): Refer to X Coding as
well.
(Communication Coding): Document that locale-coding-system is
not always used on X to decode keyboard input.
(X Coding): New node.
* etc/NEWS: Announce change to input method coding resolution.
* lisp/term/x-win.el (x-get-input-coding-system): New function.
* src/coding.c (syms_of_coding): Update doc string of
locale-coding-system.
* src/xfns.c (struct x_xim_text_conversion_data)
(x_xim_text_to_utf8_unix_1, x_xim_text_to_utf8_unix_2)
(x_xim_text_to_utf8_unix): Accept dpyinfo.  Use the coding
system specified inside if possible.
(xic_preedit_draw_callback): Pass dpyinfo.
* src/xterm.c (handle_one_xevent): Use XIM coding system for IM
input.
(xim_open_dpy): Try to determine the input method coding system.
(mark_xterm): Mark `xim_coding'.
(syms_of_xterm): New variable `x-input-coding-system'.
* src/xterm.h (struct x_display_info): New field `xim_coding'.
(FRAME_X_XIM_CODING): New macro.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/coding.c b/src/coding.c
index 0ae8eb3282b..ab73bda8440 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -12014,9 +12014,9 @@ See also the function `find-operation-coding-system'.  */);
   Vnetwork_coding_system_alist = Qnil;
 
   DEFVAR_LISP ("locale-coding-system", Vlocale_coding_system,
-               doc: /* Coding system to use with system messages.
-Also used for decoding keyboard input on X Window system, and for
-encoding standard output and error streams.  */);
+    doc: /* Coding system to use with system messages.
+Potentially also used for decoding keyboard input on X Windows, and is
+used for encoding standard output and error streams.  */);
   Vlocale_coding_system = Qnil;
 
   /* The eol mnemonics are reset in startup.el system-dependently.  */