refactor(options): use schar_T representation for fillchars and listchars

A bit big, but practically it was a lot simpler to change over all
fillchars and all listchars at once, to not need to maintain two
parallel implementations.

This is mostly an internal refactor, but it also removes an arbitrary
limitation: that 'fillchars' and 'listchars' values can only be
single-codepoint characters. Now any character which fits into a single
screen cell can be used.

1 files changed, 48 insertions, 58 deletions

diff --git a/src/nvim/message.c b/src/nvim/message.c
index 7527349e5e..2b668db7cd 100644
--- a/src/nvim/message.c
+++ b/src/nvim/message.c
@@ -143,9 +143,8 @@ static int msg_grid_pos_at_flush = 0;
 
 static void ui_ext_msg_set_pos(int row, bool scrolled)
 {
-  char buf[MB_MAXCHAR + 1];
-  size_t size = (size_t)utf_char2bytes(curwin->w_p_fcs_chars.msgsep, buf);
-  buf[size] = '\0';
+  char buf[MAX_SCHAR_SIZE];
+  size_t size = schar_get(buf, curwin->w_p_fcs_chars.msgsep);
   ui_call_msg_set_pos(msg_grid.handle, row, scrolled,
                       (String){ .data = buf, .size = size });
 }
@@ -1798,12 +1797,12 @@ void str2specialbuf(const char *sp, char *buf, size_t len)
 /// print line for :print or :list command
 void msg_prt_line(const char *s, bool list)
 {
-  int c;
+  schar_T sc;
   int col = 0;
   int n_extra = 0;
-  int c_extra = 0;
-  int c_final = 0;
-  const char *p_extra = NULL;  // init to make SASC shut up
+  schar_T sc_extra = 0;
+  schar_T sc_final = 0;
+  const char *p_extra = NULL;  // init to make SASC shut up. ASCII only!
   int n;
   int attr = 0;
   const char *lead = NULL;
@@ -1845,13 +1844,13 @@ void msg_prt_line(const char *s, bool list)
   while (!got_int) {
     if (n_extra > 0) {
       n_extra--;
-      if (n_extra == 0 && c_final) {
-        c = c_final;
-      } else if (c_extra) {
-        c = c_extra;
+      if (n_extra == 0 && sc_final) {
+        sc = sc_final;
+      } else if (sc_extra) {
+        sc = sc_extra;
       } else {
         assert(p_extra != NULL);
-        c = (unsigned char)(*p_extra++);
+        sc = schar_from_ascii((unsigned char)(*p_extra++));
       }
     } else if ((l = utfc_ptr2len(s)) > 1) {
       col += utf_ptr2cells(s);
@@ -1859,10 +1858,8 @@ void msg_prt_line(const char *s, bool list)
       if (l >= MB_MAXBYTES) {
         xstrlcpy(buf, "?", sizeof(buf));
       } else if (curwin->w_p_lcs_chars.nbsp != NUL && list
-                 && (utf_ptr2char(s) == 160
-                     || utf_ptr2char(s) == 0x202f)) {
-        int len = utf_char2bytes(curwin->w_p_lcs_chars.nbsp, buf);
-        buf[len] = NUL;
+                 && (utf_ptr2char(s) == 160 || utf_ptr2char(s) == 0x202f)) {
+        schar_get(buf, curwin->w_p_lcs_chars.nbsp);
       } else {
         memmove(buf, s, (size_t)l);
         buf[l] = NUL;
@@ -1872,7 +1869,9 @@ void msg_prt_line(const char *s, bool list)
       continue;
     } else {
       attr = 0;
-      c = (uint8_t)(*s++);
+      int c = (uint8_t)(*s++);
+      sc_extra = NUL;
+      sc_final = NUL;
       if (list) {
         in_multispace = c == ' ' && (*s == ' '
                                      || (col > 0 && s[-2] == ' '));
@@ -1882,74 +1881,72 @@ void msg_prt_line(const char *s, bool list)
       }
       if (c == TAB && (!list || curwin->w_p_lcs_chars.tab1)) {
         // tab amount depends on current column
-        n_extra = tabstop_padding(col,
-                                  curbuf->b_p_ts,
+        n_extra = tabstop_padding(col, curbuf->b_p_ts,
                                   curbuf->b_p_vts_array) - 1;
         if (!list) {
-          c = ' ';
-          c_extra = ' ';
-          c_final = NUL;
+          sc = schar_from_ascii(' ');
+          sc_extra = schar_from_ascii(' ');
         } else {
-          c = (n_extra == 0 && curwin->w_p_lcs_chars.tab3)
-              ? curwin->w_p_lcs_chars.tab3
-              : curwin->w_p_lcs_chars.tab1;
-          c_extra = curwin->w_p_lcs_chars.tab2;
-          c_final = curwin->w_p_lcs_chars.tab3;
+          sc = (n_extra == 0 && curwin->w_p_lcs_chars.tab3)
+               ? curwin->w_p_lcs_chars.tab3
+               : curwin->w_p_lcs_chars.tab1;
+          sc_extra = curwin->w_p_lcs_chars.tab2;
+          sc_final = curwin->w_p_lcs_chars.tab3;
           attr = HL_ATTR(HLF_0);
         }
-      } else if (c == 160 && list && curwin->w_p_lcs_chars.nbsp != NUL) {
-        c = curwin->w_p_lcs_chars.nbsp;
-        attr = HL_ATTR(HLF_0);
       } else if (c == NUL && list && curwin->w_p_lcs_chars.eol != NUL) {
         p_extra = "";
-        c_extra = NUL;
-        c_final = NUL;
         n_extra = 1;
-        c = curwin->w_p_lcs_chars.eol;
+        sc = curwin->w_p_lcs_chars.eol;
         attr = HL_ATTR(HLF_AT);
         s--;
       } else if (c != NUL && (n = byte2cells(c)) > 1) {
         n_extra = n - 1;
         p_extra = transchar_byte_buf(NULL, c);
-        c_extra = NUL;
-        c_final = NUL;
-        c = (unsigned char)(*p_extra++);
+        sc = schar_from_ascii(*p_extra++);
         // Use special coloring to be able to distinguish <hex> from
         // the same in plain text.
         attr = HL_ATTR(HLF_0);
       } else if (c == ' ') {
         if (lead != NULL && s <= lead && in_multispace
             && curwin->w_p_lcs_chars.leadmultispace != NULL) {
-          c = curwin->w_p_lcs_chars.leadmultispace[multispace_pos++];
+          sc = curwin->w_p_lcs_chars.leadmultispace[multispace_pos++];
           if (curwin->w_p_lcs_chars.leadmultispace[multispace_pos] == NUL) {
             multispace_pos = 0;
           }
           attr = HL_ATTR(HLF_0);
         } else if (lead != NULL && s <= lead && curwin->w_p_lcs_chars.lead != NUL) {
-          c = curwin->w_p_lcs_chars.lead;
+          sc = curwin->w_p_lcs_chars.lead;
           attr = HL_ATTR(HLF_0);
         } else if (trail != NULL && s > trail) {
-          c = curwin->w_p_lcs_chars.trail;
+          sc = curwin->w_p_lcs_chars.trail;
           attr = HL_ATTR(HLF_0);
         } else if (in_multispace
                    && curwin->w_p_lcs_chars.multispace != NULL) {
-          c = curwin->w_p_lcs_chars.multispace[multispace_pos++];
+          sc = curwin->w_p_lcs_chars.multispace[multispace_pos++];
           if (curwin->w_p_lcs_chars.multispace[multispace_pos] == NUL) {
             multispace_pos = 0;
           }
           attr = HL_ATTR(HLF_0);
         } else if (list && curwin->w_p_lcs_chars.space != NUL) {
-          c = curwin->w_p_lcs_chars.space;
+          sc = curwin->w_p_lcs_chars.space;
           attr = HL_ATTR(HLF_0);
+        } else {
+          sc = schar_from_ascii(' ');  // SPACE!
         }
+      } else {
+        sc = schar_from_ascii(c);
       }
     }
 
-    if (c == NUL) {
+    if (sc == NUL) {
       break;
     }
 
-    msg_putchar_attr(c, attr);
+    // TODO(bfredl): this is such baloney. need msg_put_schar
+    char buf[MAX_SCHAR_SIZE];
+    schar_get(buf, sc);
+    msg_puts_attr(buf, attr);
     col++;
   }
   msg_clr_eos();
@@ -2308,7 +2305,7 @@ void msg_scroll_up(bool may_throttle, bool zerocmd)
     msg_grid.dirty_col[msg_grid.rows - 1] = 0;
   }
 
-  grid_fill(&msg_grid_adj, Rows - 1, Rows, 0, Columns, ' ', ' ', HL_ATTR(HLF_MSG));
+  grid_clear(&msg_grid_adj, Rows - 1, Rows, 0, Columns, HL_ATTR(HLF_MSG));
 }
 
 /// Send throttled message output to UI clients
@@ -2823,16 +2820,14 @@ static bool do_more_prompt(int typed_char)
 
           if (toscroll == -1 && !to_redraw) {
             grid_ins_lines(&msg_grid_adj, 0, 1, Rows, 0, Columns);
-            grid_fill(&msg_grid_adj, 0, 1, 0, Columns, ' ', ' ',
-                      HL_ATTR(HLF_MSG));
+            grid_clear(&msg_grid_adj, 0, 1, 0, Columns, HL_ATTR(HLF_MSG));
             // display line at top
             disp_sb_line(0, mp);
           } else {
             // redisplay all lines
             // TODO(bfredl): this case is not optimized (though only concerns
             // event fragmentation, not unnecessary scroll events).
-            grid_fill(&msg_grid_adj, 0, Rows, 0, Columns, ' ', ' ',
-                      HL_ATTR(HLF_MSG));
+            grid_clear(&msg_grid_adj, 0, Rows, 0, Columns, HL_ATTR(HLF_MSG));
             for (int i = 0; mp != NULL && i < Rows - 1; i++) {
               mp = disp_sb_line(i, mp);
               msg_scrolled++;
@@ -2858,8 +2853,7 @@ static bool do_more_prompt(int typed_char)
           // scroll up, display line at bottom
           msg_scroll_up(true, false);
           inc_msg_scrolled();
-          grid_fill(&msg_grid_adj, Rows - 2, Rows - 1, 0, Columns, ' ', ' ',
-                    HL_ATTR(HLF_MSG));
+          grid_clear(&msg_grid_adj, Rows - 2, Rows - 1, 0, Columns, HL_ATTR(HLF_MSG));
           mp_last = disp_sb_line(Rows - 2, mp_last);
           toscroll--;
         }
@@ -2867,8 +2861,7 @@ static bool do_more_prompt(int typed_char)
 
       if (toscroll <= 0) {
         // displayed the requested text, more prompt again
-        grid_fill(&msg_grid_adj, Rows - 1, Rows, 0, Columns, ' ', ' ',
-                  HL_ATTR(HLF_MSG));
+        grid_clear(&msg_grid_adj, Rows - 1, Rows, 0, Columns, HL_ATTR(HLF_MSG));
         msg_moremsg(false);
         continue;
       }
@@ -2881,8 +2874,7 @@ static bool do_more_prompt(int typed_char)
   }
 
   // clear the --more-- message
-  grid_fill(&msg_grid_adj, Rows - 1, Rows, 0, Columns, ' ', ' ',
-            HL_ATTR(HLF_MSG));
+  grid_clear(&msg_grid_adj, Rows - 1, Rows, 0, Columns, HL_ATTR(HLF_MSG));
   redraw_cmdline = true;
   clear_cmdline = false;
   mode_displayed = false;
@@ -2966,10 +2958,8 @@ void msg_clr_eos_force(void)
     }
   }
 
-  grid_fill(&msg_grid_adj, msg_row, msg_row + 1, msg_startcol, msg_endcol,
-            ' ', ' ', HL_ATTR(HLF_MSG));
-  grid_fill(&msg_grid_adj, msg_row + 1, Rows, 0, Columns,
-            ' ', ' ', HL_ATTR(HLF_MSG));
+  grid_clear(&msg_grid_adj, msg_row, msg_row + 1, msg_startcol, msg_endcol, HL_ATTR(HLF_MSG));
+  grid_clear(&msg_grid_adj, msg_row + 1, Rows, 0, Columns, HL_ATTR(HLF_MSG));
 
   redraw_cmdline = true;  // overwritten the command line
   if (msg_row < Rows - 1 || msg_col == 0) {