Fix more problems found by GCC 4.6.0's static checks.

diff --cc lib-src/ChangeLog
index f594efa,1c0c506..5007995
--- 1/lib-src/ChangeLog
--- 2/lib-src/ChangeLog
+++ b/lib-src/ChangeLog
@@@ -1,3 -1,7 +1,8 @@@
 -2011-03-29  Paul Eggert  <eggert@cs.ucla.edu>
++2011-03-30  Paul Eggert  <eggert@cs.ucla.edu>
+ 
++      Fix a problem found by GCC 4.6.0's static checks.
+       * etags.c (just_read_file): Remove dummy variable and simplify.
+ 
  2011-03-27  Glenn Morris  <rgm@gnu.org>
  
        * emacsclient.c: Replace SIGTYPE with void.

diff --cc src/ChangeLog
index 1e77a64,c44444a..973b771
--- 1/src/ChangeLog
--- 2/src/ChangeLog
+++ b/src/ChangeLog
@@@ -1,3 -1,76 +1,76 @@@
 -2011-03-29  Paul Eggert  <eggert@cs.ucla.edu>
 -
+ 2011-03-30  Paul Eggert  <eggert@cs.ucla.edu>
+ 
++      Fix more problems found by GCC 4.6.0's static checks.
++
+       * unexelf.c (unexec) [! (defined _SYSTYPE_SYSV || defined __sgi)]:
+       Remove unused local var.
+ 
+       * editfns.c (Fmessage_box): Remove unused local var.
+ 
 -      All variadic functions changed accordingly.
+       * xdisp.c (try_window_reusing_current_matrix, x_produce_glyphs):
+       (note_mode_line_or_margin_highlight, note_mouse_highlight):
+       Omit unused local vars.
+       * window.c (shrink_windows): Omit unused local var.
+       * menu.c (digest_single_submenu): Omit unused local var.
+       * dispnew.c (update_window) [PERIODIC_PREEMPTION_CHECKING]:
+       Omit unused local var.
+ 
+       * keyboard.c (parse_modifiers_uncached, parse_modifiers):
+       Don't assume string length fits in int.
+       (keyremap_step, read_key_sequence): Use size_t for sizes.
+       (read_key_sequence): Don't check last_real_key_start redundantly.
+ 
+       * callproc.c (Fcall_process, Fcall_process_region): Use SAFE_ALLOCA
+       instead of alloca (Bug#8344).
+ 
+       * eval.c (Fbacktrace): Don't assume nargs fits in int.
+       (Fbacktrace_frame): Don't assume nframes fits in int.
+ 
+       * syntax.c (scan_sexps_forward): Avoid pointer wraparound.
+ 
+       * xterm.c (x_make_frame_visible, same_x_server): Redo to avoid overflow
+       concerns.
+ 
+       * term.c (produce_glyphless_glyph): Remove unnecessary test.
+ 
+       * cm.c (calccost): Turn while-do into do-while, for clarity.
+ 
+       * keyboard.c (syms_of_keyboard): Use the same style as later
+       in this function when indexing through an array.  This also
+       works around GCC bug 48267.
+ 
+       * image.c (tiff_load): Fix off-by-one image count (Bug#8336).
+ 
+       * xselect.c (x_check_property_data): Return correct size (Bug#8335).
+ 
+       * chartab.c (sub_char_table_ref_and_range): Redo for slight
+       efficiency gain, and to bypass a gcc -Wstrict-overflow warning.
+ 
+       * keyboard.c, keyboard.h (num_input_events): Now size_t.
+       This avoids undefined behavior on integer overflow, and is a bit
+       more convenient anyway since it is compared to a size_t variable.
+ 
+       Variadic C functions now count arguments with size_t, not int.
+       This avoids an unnecessary limitation on 64-bit machines, which
+       caused (substring ...) to crash on large vectors (Bug#8344).
+       * lisp.h (struct Lisp_Subr.function.aMANY): Now takes size_t, not int.
+       (DEFUN_ARGS_MANY, internal_condition_case_n, safe_call): Likewise.
++      All variadic functions and their callers changed accordingly.
+       (struct gcpro.nvars): Now size_t, not int.  All uses changed.
+       * data.c (arith_driver, float_arith_driver): Likewise.
+       * editfns.c (general_insert_function): Likewise.
+       * eval.c (struct backtrace.nargs, interactive_p)
+       (internal_condition_case_n, run_hook_with_args, apply_lambda)
+       (funcall_lambda, mark_backtrace): Likewise.
+       * fns.c (concat): Likewise.
+       * frame.c (x_set_frame_parameters): Likewise.
+       * fns.c (get_key_arg): Now accepts and returns size_t, and returns
+       0 if not found, not -1.  All callers changed.
+ 
+       * alloc.c (garbage_collect): Don't assume stack size fits in int.
+       (stack_copy_size): Now size_t, not int.
+       (stack_copy, stack_copy_size): Define only if MAX_SAVE_STACK > 0.
+ 
  2011-03-28  Juanma Barranquero  <lekktu@gmail.com>
  
        * coding.c (encode_designation_at_bol): Remove parameter `charbuf_end',

diff --cc src/eval.c
index 7587436,c3f9cd1..26aea3d
--- 1/src/eval.c
--- 2/src/eval.c
+++ b/src/eval.c
@@@ -37,10 -37,10 +37,10 @@@ struct backtrac
  {
    struct backtrace *next;
    Lisp_Object *function;
 -  Lisp_Object *args;  /* Points to vector of args. */
 +  Lisp_Object *args;  /* Points to vector of args.  */
-   int nargs;          /* Length of vector.
-                          If nargs is UNEVALLED, args points to slot holding
-                          list of unevalled args.  */
+   size_t nargs;               /* Length of vector.
+                          If nargs is (size_t) UNEVALLED, args points
+                          to slot holding list of unevalled args.  */
    char evalargs;
    /* Nonzero means call value of debugger when done with this operation.  */
    char debug_on_exit;