fold: add const to hasFoldingWin() variables

cache is bool so update callers to pass true/false, not TRUE/FALSE.

src/nvim/diff.c

@@ -1486,7 +1486,7 @@ int diff_check(win_T *wp, linenr_T lnum)
   }
 
   // A closed fold never has filler lines.
-  if (hasFoldingWin(wp, lnum, NULL, NULL, TRUE, NULL)) {
+  if (hasFoldingWin(wp, lnum, NULL, NULL, true, NULL)) {
     return 0;
   }
 
@@ -1793,7 +1793,7 @@ void diff_set_topline(win_T *fromwin, win_T *towin)
 
   check_topfill(towin, false);
   (void)hasFoldingWin(towin, towin->w_topline, &towin->w_topline,
-                      NULL, TRUE, NULL);
+                      NULL, true, NULL);
 }
 
 /// This is called when 'diffopt' is changed.

src/nvim/fold.c

@@ -147,29 +147,27 @@ int hasAnyFolding(win_T *win)
  */
 bool hasFolding(linenr_T lnum, linenr_T *firstp, linenr_T *lastp)
 {
-  return hasFoldingWin(curwin, lnum, firstp, lastp, TRUE, NULL);
+  return hasFoldingWin(curwin, lnum, firstp, lastp, true, NULL);
 }
 
 /* hasFoldingWin() {{{2 */
 bool hasFoldingWin(
-    win_T *win,
+    win_T *const win,
-    linenr_T lnum,
+    const linenr_T lnum,
-    linenr_T *firstp,
+    linenr_T *const firstp,
-    linenr_T *lastp,
+    linenr_T *const lastp,
-    int cache,                      /* when TRUE: use cached values of window */
+    const bool cache,             // when true: use cached values of window
-    foldinfo_T *infop             /* where to store fold info */
+    foldinfo_T *const infop       // where to store fold info
 )
 {
   bool had_folded = false;
   linenr_T first = 0;
   linenr_T last = 0;
   linenr_T lnum_rel = lnum;
-  int x;
   fold_T      *fp;
   int level = 0;
   bool use_level = false;
   bool maybe_small = false;
-  garray_T    *gap;
   int low_level = 0;
 
   checkupdate(win);
@@ -187,7 +185,7 @@ bool hasFoldingWin(
      * First look in cached info for displayed lines.  This is probably
      * the fastest, but it can only be used if the entry is still valid.
      */
-    x = find_wl_entry(win, lnum);
+    const int x = find_wl_entry(win, lnum);
     if (x >= 0) {
       first = win->w_lines[x].wl_lnum;
       last = win->w_lines[x].wl_lastlnum;
@@ -199,7 +197,7 @@ bool hasFoldingWin(
     /*
      * Recursively search for a fold that contains "lnum".
      */
-    gap = &win->w_folds;
+    garray_T *gap = &win->w_folds;
     for (;; ) {
       if (!foldFind(gap, lnum_rel, &fp))
         break;
@@ -296,8 +294,9 @@ long foldedCount(win_T *win, linenr_T lnum, foldinfo_T *infop)
 {
   linenr_T last;
 
-  if (hasFoldingWin(win, lnum, NULL, &last, FALSE, infop))
+  if (hasFoldingWin(win, lnum, NULL, &last, false, infop)) {
     return (long)(last - lnum + 1);
+  }
   return 0;
 }
 

src/nvim/screen.c

@@ -783,16 +783,18 @@ static void win_update(win_T *wp)
           }
         }
 
-      (void)hasFoldingWin(wp, mod_top, &mod_top, NULL, TRUE, NULL);
+      (void)hasFoldingWin(wp, mod_top, &mod_top, NULL, true, NULL);
-      if (mod_top > lnumt)
+      if (mod_top > lnumt) {
         mod_top = lnumt;
+      }
 
-      /* Now do the same for the bottom line (one above mod_bot). */
+      // Now do the same for the bottom line (one above mod_bot).
-      --mod_bot;
+      mod_bot--;
-      (void)hasFoldingWin(wp, mod_bot, NULL, &mod_bot, TRUE, NULL);
+      (void)hasFoldingWin(wp, mod_bot, NULL, &mod_bot, true, NULL);
-      ++mod_bot;
+      mod_bot++;
-      if (mod_bot < lnumb)
+      if (mod_bot < lnumb) {
         mod_bot = lnumb;
+      }
     }
 
     /* When a change starts above w_topline and the end is below
@@ -876,7 +878,7 @@ static void win_update(win_T *wp)
           ++j;
           if (j >= wp->w_height - 2)
             break;
-          (void)hasFoldingWin(wp, ln, NULL, &ln, TRUE, NULL);
+          (void)hasFoldingWin(wp, ln, NULL, &ln, true, NULL);
         }
       } else
         j = wp->w_lines[0].wl_lnum - wp->w_topline;
@@ -1307,15 +1309,15 @@ static void win_update(win_T *wp)
           /* Able to count old number of rows: Count new window
            * rows, and may insert/delete lines */
           j = idx;
-          for (l = lnum; l < mod_bot; ++l) {
+          for (l = lnum; l < mod_bot; l++) {
-            if (hasFoldingWin(wp, l, NULL, &l, TRUE, NULL))
+            if (hasFoldingWin(wp, l, NULL, &l, true, NULL)) {
-              ++new_rows;
+              new_rows++;
-            else if (l == wp->w_topline)
+            } else if (l == wp->w_topline) {
-              new_rows += plines_win_nofill(wp, l, TRUE)
+              new_rows += plines_win_nofill(wp, l, true) + wp->w_topfill;
-                          + wp->w_topfill;
+            } else {
-            else
+              new_rows += plines_win(wp, l, true);
-              new_rows += plines_win(wp, l, TRUE);
+            }
-            ++j;
+            j++;
             if (new_rows > wp->w_height - row - 2) {
               /* it's getting too much, must redraw the rest */
               new_rows = 9999;
@@ -5525,10 +5527,12 @@ static void prepare_search_hl(win_T *wp, linenr_T lnum)
         && re_multiline(shl->rm.regprog)) {
       if (shl->first_lnum == 0) {
         for (shl->first_lnum = lnum;
-             shl->first_lnum > wp->w_topline; --shl->first_lnum)
+             shl->first_lnum > wp->w_topline;
-          if (hasFoldingWin(wp, shl->first_lnum - 1,
+             shl->first_lnum--) {
-                  NULL, NULL, TRUE, NULL))
+          if (hasFoldingWin(wp, shl->first_lnum - 1, NULL, NULL, true, NULL)) {
             break;
+          }
+        }
       }
       if (cur != NULL) {
         cur->pos.cur = 0;