* cm.c (calccost, cmgoto): Use const pointers where appropriate.

* cm.h (struct cm): Likewise.
* dispextern.h (do_line_insertion_deletion_costs): Likewise.
* scroll.c (ins_del_costs, do_line_insertion_deletion_costs): Likewise.
* term.c (tty_ins_del_lines, calculate_costs, struct fkey_table):
(term_get_fkeys_1, append_glyphless_glyph, produce_glyphless_glyph):
(turn_on_face, init_tty): Likewise.
* termchar.h (struct tty_display_info): Likewise.
* term.c (tgetflag, tgetnum, tgetstr): Redefine to use const pointers.

7 files changed, 120 insertions, 93 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 350f01953d4..a8594fb3fc6 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -98,6 +98,16 @@
         * tparam.c (tparam1, tparam, tgoto):
         Use const pointers where appropriate.
 
+        * cm.c (calccost, cmgoto): Use const pointers where appropriate.
+        * cm.h (struct cm): Likewise.
+        * dispextern.h (do_line_insertion_deletion_costs): Likewise.
+        * scroll.c (ins_del_costs, do_line_insertion_deletion_costs): Likewise.
+        * term.c (tty_ins_del_lines, calculate_costs, struct fkey_table):
+        (term_get_fkeys_1, append_glyphless_glyph, produce_glyphless_glyph):
+        (turn_on_face, init_tty): Likewise.
+        * termchar.h (struct tty_display_info): Likewise.
+        * term.c (tgetflag, tgetnum, tgetstr): Redefine to use const pointers.
+
 2011-03-06  Chong Yidong  <cyd@stupidchicken.com>
 
         * xdisp.c (redisplay_window): Revert incorrect logic in 2011-03-06
diff --git a/src/cm.c b/src/cm.c
index af4116f3fec..108ee5720f3 100644
--- a/src/cm.c
+++ b/src/cm.c
@@ -199,7 +199,7 @@ calccost (struct tty_display_info *tty,
             tabx,
             tab2x,
             tabcost;
-    register char  *p;
+    register const char *p;
 
     /* If have just wrapped on a terminal with xn,
        don't believe the cursor position: give up here
@@ -331,8 +331,8 @@ cmgoto (struct tty_display_info *tty, int row, int col)
             relcost,
             directcost;
     int     use IF_LINT (= 0);
-    char   *p,
-           *dcm;
+    char *p;
+    const char *dcm;
 
   /* First the degenerate case */
     if (row == curY (tty) && col == curX (tty)) /* already there */
diff --git a/src/cm.h b/src/cm.h
index 7b4bedd4e88..5d430598f0c 100644
--- a/src/cm.h
+++ b/src/cm.h
@@ -35,25 +35,25 @@ struct cm
     int cm_curX;                        /* Current column */
 
     /* Capabilities from termcap */
-    char *cm_up;                /* up (up) */
-    char *cm_down;              /* down (do) */
-    char *cm_left;              /* left (le) */
-    char *cm_right;             /* right (nd) */
-    char *cm_home;              /* home (ho) */
-    char *cm_cr;                /* carriage return (cr) */
-    char *cm_ll;                /* last line (ll) */
-    char *cm_tab;               /* tab (ta) */
-    char *cm_backtab;           /* backtab (bt) */
+    const char *cm_up;          /* up (up) */
+    const char *cm_down;        /* down (do) */
+    const char *cm_left;        /* left (le) */
+    const char *cm_right;       /* right (nd) */
+    const char *cm_home;        /* home (ho) */
+    const char *cm_cr;          /* carriage return (cr) */
+    const char *cm_ll;          /* last line (ll) */
+    const char *cm_tab;         /* tab (ta) */
+    const char *cm_backtab;     /* backtab (bt) */
     char *cm_abs;               /* absolute (cm) */
-    char *cm_habs;              /* horizontal absolute (ch) */
-    char *cm_vabs;              /* vertical absolute (cv) */
+    const char *cm_habs;        /* horizontal absolute (ch) */
+    const char *cm_vabs;        /* vertical absolute (cv) */
 #if 0
-    char *cm_ds;                /* "don't send" string (ds) */
+    const char *cm_ds;          /* "don't send" string (ds) */
 #endif
-    char *cm_multiup;           /* multiple up (UP) */
-    char *cm_multidown;         /* multiple down (DO) */
-    char *cm_multileft;         /* multiple left (LE) */
-    char *cm_multiright;        /* multiple right (RI) */
+    const char *cm_multiup;     /* multiple up (UP) */
+    const char *cm_multidown;   /* multiple down (DO) */
+    const char *cm_multileft;   /* multiple left (LE) */
+    const char *cm_multiright;  /* multiple right (RI) */
     int cm_cols;                /* number of cols on screen (co) */
     int cm_rows;                /* number of rows on screen (li) */
     int cm_tabwidth;            /* tab width (it) */
@@ -168,4 +168,3 @@ extern void cmcostinit (struct tty_display_info *);
 extern void cmgoto (struct tty_display_info *, int, int);
 extern void Wcm_clear (struct tty_display_info *);
 extern int Wcm_init (struct tty_display_info *);
-
diff --git a/src/dispextern.h b/src/dispextern.h
index 30979d487ff..9843dfd1fcd 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3326,9 +3326,10 @@ extern struct terminal *init_tty (const char *, const char *, int);
 
 extern int scrolling_max_lines_saved (int, int, int *, int *, int *);
 extern int scroll_cost (struct frame *, int, int, int);
-extern void do_line_insertion_deletion_costs (struct frame *, char *,
-                                              char *, char *, char *,
-                                              char *, char *, int);
+extern void do_line_insertion_deletion_costs (struct frame *, const char *,
+                                              const char *, const char *,
+                                              const char *, const char *,
+                                              const char *, int);
 void scrolling_1 (struct frame *, int, int, int, int *, int *, int *,
                   int *, int);
 
diff --git a/src/scroll.c b/src/scroll.c
index 1343b89c41e..33af18d2090 100644
--- a/src/scroll.c
+++ b/src/scroll.c
@@ -938,8 +938,8 @@ line_ins_del (FRAME_PTR frame, int ov1, int pf1, int ovn, int pfn, register int
 
 static void
 ins_del_costs (FRAME_PTR frame,
-               char *one_line_string, char *multi_string,
-               char *setup_string, char *cleanup_string,
+               const char *one_line_string, const char *multi_string,
+               const char *setup_string, const char *cleanup_string,
                int *costvec, int *ncostvec,
                int coefficient)
 {
@@ -994,9 +994,12 @@ ins_del_costs (FRAME_PTR frame,
 
 void
 do_line_insertion_deletion_costs (FRAME_PTR frame,
-                                  char *ins_line_string, char *multi_ins_string,
-                                  char *del_line_string, char *multi_del_string,
-                                  char *setup_string, char *cleanup_string,
+                                  const char *ins_line_string,
+                                  const char *multi_ins_string,
+                                  const char *del_line_string,
+                                  const char *multi_del_string,
+                                  const char *setup_string,
+                                  const char *cleanup_string,
                                   int coefficient)
 {
   if (FRAME_INSERT_COST (frame) != 0)
diff --git a/src/term.c b/src/term.c
index 19d7d893069..6986cfb9e03 100644
--- a/src/term.c
+++ b/src/term.c
@@ -961,9 +961,10 @@ static void
 tty_ins_del_lines (struct frame *f, int vpos, int n)
 {
   struct tty_display_info *tty = FRAME_TTY (f);
-  char *multi = n > 0 ? tty->TS_ins_multi_lines : tty->TS_del_multi_lines;
-  char *single = n > 0 ? tty->TS_ins_line : tty->TS_del_line;
-  char *scroll = n > 0 ? tty->TS_rev_scroll : tty->TS_fwd_scroll;
+  const char *multi =
+    n > 0 ? tty->TS_ins_multi_lines : tty->TS_del_multi_lines;
+  const char *single = n > 0 ? tty->TS_ins_line : tty->TS_del_line;
+  const char *scroll = n > 0 ? tty->TS_rev_scroll : tty->TS_fwd_scroll;
 
   register int i = n > 0 ? n : -n;
   register char *buf;
@@ -1138,9 +1139,9 @@ calculate_costs (struct frame *frame)
   if (FRAME_TERMCAP_P (frame))
     {
       struct tty_display_info *tty = FRAME_TTY (frame);
-      register char *f = (tty->TS_set_scroll_region
-                          ? tty->TS_set_scroll_region
-                          : tty->TS_set_scroll_region_1);
+      register const char *f = (tty->TS_set_scroll_region
+                                ? tty->TS_set_scroll_region
+                                : tty->TS_set_scroll_region_1);
 
       FRAME_SCROLL_REGION_COST (frame) = string_cost (f);
 
@@ -1194,7 +1195,7 @@ calculate_costs (struct frame *frame)
 }
 
 struct fkey_table {
-  char *cap, *name;
+  const char *cap, *name;
 };
 
   /* Termcap capability names that correspond directly to X keysyms.
@@ -1305,6 +1306,18 @@ static char **term_get_fkeys_address;
 static KBOARD *term_get_fkeys_kboard;
 static Lisp_Object term_get_fkeys_1 (void);
 
+/* Rework termcap API to accept const pointer args.  */
+static inline int my_tgetflag (const char *x) { return tgetflag ((char *) x); }
+static inline int my_tgetnum (const char *x) { return tgetnum ((char *) x); }
+static inline char *my_tgetstr (const char *x, char **a)
+{ return tgetstr ((char *) x, a); }
+#undef tgetflag
+#undef tgetnum
+#undef tgetstr
+#define tgetflag my_tgetflag
+#define tgetnum my_tgetnum
+#define tgetstr my_tgetstr
+
 /* Find the escape codes sent by the function keys for Vinput_decode_map.
    This function scans the termcap function key sequence entries, and
    adds entries to Vinput_decode_map for each function key it finds.  */
@@ -1352,9 +1365,9 @@ term_get_fkeys_1 (void)
      "k;", and if it is present, assuming that "k0" denotes F0, otherwise F10.
      */
   {
-    char *k_semi  = tgetstr ("k;", address);
-    char *k0      = tgetstr ("k0", address);
-    char *k0_name = "f10";
+    const char *k_semi  = tgetstr ("k;", address);
+    const char *k0      = tgetstr ("k0", address);
+    const char *k0_name = "f10";
 
     if (k_semi)
       {
@@ -1447,7 +1460,7 @@ static void append_glyph (struct it *);
 static void produce_stretch_glyph (struct it *);
 static void append_composite_glyph (struct it *);
 static void produce_composite_glyph (struct it *);
-static void append_glyphless_glyph (struct it *, int, char *);
+static void append_glyphless_glyph (struct it *, int, const char *);
 static void produce_glyphless_glyph (struct it *, int, Lisp_Object);
 
 /* Append glyphs to IT's glyph_row.  Called from produce_glyphs for
@@ -1815,7 +1828,7 @@ produce_composite_glyph (struct it *it)
    comes from it->nglyphs bytes).  */
 
 static void
-append_glyphless_glyph (struct it *it, int face_id, char *str)
+append_glyphless_glyph (struct it *it, int face_id, const char *str)
 {
   struct glyph *glyph, *end;
   int i;
@@ -1890,7 +1903,8 @@ produce_glyphless_glyph (struct it *it, int for_no_font, Lisp_Object acronym)
 {
   int face_id;
   int len;
-  char buf[9], *str = "    ";
+  char buf[9];
+  char const *str = "    ";
 
   /* Get a face ID for the glyph by utilizing a cache (the same way as
      done for `escape-glyph' in get_next_display_element).  */
@@ -2109,7 +2123,8 @@ turn_on_face (struct frame *f, int face_id)
 
   if (tty->TN_max_colors > 0)
     {
-      char *ts, *p;
+      const char *ts;
+      char *p;
 
       ts = tty->standout_mode ? tty->TS_set_background : tty->TS_set_foreground;
       if (fg >= 0 && ts)
@@ -3519,10 +3534,10 @@ use the Bourne shell command `TERM=... export TERM' (C-shell:\n\
          If it were in the termcap entry, it would confuse other programs.  */
       if (!tty->TS_set_window)
         {
-          p = tty->TS_termcap_modes;
-          while (*p && strcmp (p, "\033v  "))
-            p++;
-          if (*p)
+          const char *m = tty->TS_termcap_modes;
+          while (*m && strcmp (m, "\033v  "))
+            m++;
+          if (*m)
             tty->TS_set_window = "\033v%C %C %C %C ";
         }
       /* Termcap entry often fails to have :in: flag */
diff --git a/src/termchar.h b/src/termchar.h
index 277a96932b4..035974a8ce6 100644
--- a/src/termchar.h
+++ b/src/termchar.h
@@ -84,58 +84,58 @@ struct tty_display_info
 
   /* Strings, numbers and flags taken from the termcap entry.  */
 
-  char *TS_ins_line;            /* "al" */
-  char *TS_ins_multi_lines;     /* "AL" (one parameter, # lines to insert) */
-  char *TS_bell;                /* "bl" */
-  char *TS_clr_to_bottom;       /* "cd" */
-  char *TS_clr_line;            /* "ce", clear to end of line */
-  char *TS_clr_frame;           /* "cl" */
-  char *TS_set_scroll_region;   /* "cs" (2 params, first line and last line) */
-  char *TS_set_scroll_region_1; /* "cS" (4 params: total lines,
+  const char *TS_ins_line;      /* "al" */
+  const char *TS_ins_multi_lines; /* "AL" (one parameter, # lines to insert) */
+  const char *TS_bell;          /* "bl" */
+  const char *TS_clr_to_bottom; /* "cd" */
+  const char *TS_clr_line;      /* "ce", clear to end of line */
+  const char *TS_clr_frame;     /* "cl" */
+  const char *TS_set_scroll_region; /* "cs" (2 params, first line and last line) */
+  const char *TS_set_scroll_region_1; /* "cS" (4 params: total lines,
                                    lines above scroll region, lines below it,
                                    total lines again) */
-  char *TS_del_char;            /* "dc" */
-  char *TS_del_multi_chars;     /* "DC" (one parameter, # chars to delete) */
-  char *TS_del_line;            /* "dl" */
-  char *TS_del_multi_lines;     /* "DL" (one parameter, # lines to delete) */
-  char *TS_delete_mode;         /* "dm", enter character-delete mode */
-  char *TS_end_delete_mode;     /* "ed", leave character-delete mode */
-  char *TS_end_insert_mode;     /* "ei", leave character-insert mode */
-  char *TS_ins_char;            /* "ic" */
-  char *TS_ins_multi_chars;     /* "IC" (one parameter, # chars to insert) */
-  char *TS_insert_mode;         /* "im", enter character-insert mode */
-  char *TS_pad_inserted_char;   /* "ip".  Just padding, no commands.  */
-  char *TS_end_keypad_mode;     /* "ke" */
-  char *TS_keypad_mode;         /* "ks" */
-  char *TS_pad_char;            /* "pc", char to use as padding */
-  char *TS_repeat;              /* "rp" (2 params, # times to repeat
+  const char *TS_del_char;      /* "dc" */
+  const char *TS_del_multi_chars; /* "DC" (one parameter, # chars to delete) */
+  const char *TS_del_line;      /* "dl" */
+  const char *TS_del_multi_lines; /* "DL" (one parameter, # lines to delete) */
+  const char *TS_delete_mode;   /* "dm", enter character-delete mode */
+  const char *TS_end_delete_mode; /* "ed", leave character-delete mode */
+  const char *TS_end_insert_mode; /* "ei", leave character-insert mode */
+  const char *TS_ins_char;      /* "ic" */
+  const char *TS_ins_multi_chars; /* "IC" (one parameter, # chars to insert) */
+  const char *TS_insert_mode;   /* "im", enter character-insert mode */
+  const char *TS_pad_inserted_char; /* "ip".  Just padding, no commands.  */
+  const char *TS_end_keypad_mode; /* "ke" */
+  const char *TS_keypad_mode;   /* "ks" */
+  const char *TS_pad_char;      /* "pc", char to use as padding */
+  const char *TS_repeat;        /* "rp" (2 params, # times to repeat
                                    and character to be repeated) */
-  char *TS_end_standout_mode;   /* "se" */
-  char *TS_fwd_scroll;          /* "sf" */
-  char *TS_standout_mode;       /* "so" */
-  char *TS_rev_scroll;          /* "sr" */
-  char *TS_end_termcap_modes;   /* "te" */
-  char *TS_termcap_modes;       /* "ti" */
-  char *TS_visible_bell;        /* "vb" */
-  char *TS_cursor_normal;       /* "ve" */
-  char *TS_cursor_visible;      /* "vs" */
-  char *TS_cursor_invisible;    /* "vi" */
-  char *TS_set_window;          /* "wi" (4 params, start and end of window,
+  const char *TS_end_standout_mode; /* "se" */
+  const char *TS_fwd_scroll;    /* "sf" */
+  const char *TS_standout_mode; /* "so" */
+  const char *TS_rev_scroll;    /* "sr" */
+  const char *TS_end_termcap_modes; /* "te" */
+  const char *TS_termcap_modes; /* "ti" */
+  const char *TS_visible_bell;  /* "vb" */
+  const char *TS_cursor_normal; /* "ve" */
+  const char *TS_cursor_visible; /* "vs" */
+  const char *TS_cursor_invisible; /* "vi" */
+  const char *TS_set_window;    /* "wi" (4 params, start and end of window,
                                    each as vpos and hpos) */
 
-  char *TS_enter_bold_mode;     /* "md" -- turn on bold (extra bright mode).  */
-  char *TS_enter_dim_mode;      /* "mh" -- turn on half-bright mode.  */
-  char *TS_enter_blink_mode;    /* "mb" -- enter blinking mode.  */
-  char *TS_enter_reverse_mode;  /* "mr" -- enter reverse video mode.  */
-  char *TS_exit_underline_mode; /* "us" -- start underlining.  */
-  char *TS_enter_underline_mode; /* "ue" -- end underlining.  */
+  const char *TS_enter_bold_mode; /* "md" -- turn on bold (extra bright mode).  */
+  const char *TS_enter_dim_mode; /* "mh" -- turn on half-bright mode.  */
+  const char *TS_enter_blink_mode; /* "mb" -- enter blinking mode.  */
+  const char *TS_enter_reverse_mode; /* "mr" -- enter reverse video mode.  */
+  const char *TS_exit_underline_mode; /* "us" -- start underlining.  */
+  const char *TS_enter_underline_mode; /* "ue" -- end underlining.  */
 
   /* "as"/"ae" -- start/end alternate character set.  Not really
      supported, yet.  */
-  char *TS_enter_alt_charset_mode;
-  char *TS_exit_alt_charset_mode;
+  const char *TS_enter_alt_charset_mode;
+  const char *TS_exit_alt_charset_mode;
 
-  char *TS_exit_attribute_mode; /* "me" -- switch appearances off.  */
+  const char *TS_exit_attribute_mode; /* "me" -- switch appearances off.  */
 
   /* Value of the "NC" (no_color_video) capability, or 0 if not present.  */
   int TN_no_color_video;
@@ -147,12 +147,12 @@ struct tty_display_info
   int TN_max_pairs;
 
   /* "op" -- SVr4 set default pair to its original value.  */
-  char *TS_orig_pair;
+  const char *TS_orig_pair;
 
   /* "AF"/"AB" or "Sf"/"Sb"-- set ANSI or SVr4 foreground/background color.
      1 param, the color index.  */
-  char *TS_set_foreground;
-  char *TS_set_background;
+  const char *TS_set_foreground;
+  const char *TS_set_background;
 
   int TF_hazeltine;             /* termcap hz flag. */
   int TF_insmode_motion;        /* termcap mi flag: can move while in insert mode. */
@@ -210,4 +210,3 @@ extern struct tty_display_info *tty_list;
    : (abort(), (struct tty_display_info *) 0))
 
 #define CURTTY() FRAME_TTY (SELECTED_FRAME())
-