refactor(grid): unused grid->line_wraps delenda est

This is not used as part of the logic to actually implement TUI line wrapping
In vim (especially gvim) it is used to emulate terminal-style text
selection. But in nvim we don't do that, and have no plans to reintroduce it.

src/nvim/drawline.c

@@ -3172,9 +3172,6 @@ int win_line(win_T *wp, linenr_T lnum, int startrow, int endrow, bool number_onl
 
         // Force a redraw of the first column of the next line.
         current_grid->attrs[current_grid->line_offset[current_row + 1]] = -1;
-
-        // Remember that the line wraps, used for modeless copy.
-        current_grid->line_wraps[current_row] = true;
       }
 
       wlv.boguscols = 0;

src/nvim/drawscreen.c

@@ -215,7 +215,6 @@ void screenclear(void)
   for (int i = 0; i < default_grid.rows; i++) {
     grid_clear_line(&default_grid, default_grid.line_offset[i],
                     default_grid.cols, true);
-    default_grid.line_wraps[i] = false;
   }
 
   ui_call_grid_clear(1);  // clear the display

src/nvim/grid.c

@@ -574,10 +574,6 @@ void grid_fill(ScreenGrid *grid, int start_row, int end_row, int start_col, int
         ui_line(grid, row, dirty_first, last, dirty_last, attr, false);
       }
     }
-
-    if (end_col == grid->cols) {
-      grid->line_wraps[row] = false;
-    }
   }
 }
 
@@ -777,12 +773,6 @@ void grid_put_linebuf(ScreenGrid *grid, int row, int coloff, int endcol, int cle
     }
   }
 
-  if (clear_width > 0 || wp->w_width != grid->cols) {
-    // If we cleared after the end of the line, it did not wrap.
-    // For vsplit, line wrapping is not possible.
-    grid->line_wraps[row] = false;
-  }
-
   if (clear_end < end_dirty) {
     clear_end = end_dirty;
   }
@@ -806,14 +796,12 @@ void grid_alloc(ScreenGrid *grid, int rows, int columns, bool copy, bool valid)
   ngrid.vcols = xmalloc(ncells * sizeof(colnr_T));
   memset(ngrid.vcols, -1, ncells * sizeof(colnr_T));
   ngrid.line_offset = xmalloc((size_t)rows * sizeof(*ngrid.line_offset));
-  ngrid.line_wraps = xmalloc((size_t)rows * sizeof(*ngrid.line_wraps));
 
   ngrid.rows = rows;
   ngrid.cols = columns;
 
   for (new_row = 0; new_row < ngrid.rows; new_row++) {
     ngrid.line_offset[new_row] = (size_t)new_row * (size_t)ngrid.cols;
-    ngrid.line_wraps[new_row] = false;
 
     grid_clear_line(&ngrid, ngrid.line_offset[new_row], columns, valid);
 
@@ -858,13 +846,11 @@ void grid_free(ScreenGrid *grid)
   xfree(grid->attrs);
   xfree(grid->vcols);
   xfree(grid->line_offset);
-  xfree(grid->line_wraps);
 
   grid->chars = NULL;
   grid->attrs = NULL;
   grid->vcols = NULL;
   grid->line_offset = NULL;
-  grid->line_wraps = NULL;
 }
 
 /// Doesn't allow reinit, so must only be called by free_all_mem!
@@ -987,16 +973,13 @@ void grid_ins_lines(ScreenGrid *grid, int row, int line_count, int end, int col,
       }
       j += line_count;
       grid_clear_line(grid, grid->line_offset[j] + (size_t)col, width, false);
-      grid->line_wraps[j] = false;
     } else {
       j = end - 1 - i;
       temp = (unsigned)grid->line_offset[j];
       while ((j -= line_count) >= row) {
         grid->line_offset[j + line_count] = grid->line_offset[j];
-        grid->line_wraps[j + line_count] = grid->line_wraps[j];
       }
       grid->line_offset[j + line_count] = temp;
-      grid->line_wraps[j + line_count] = false;
       grid_clear_line(grid, temp, grid->cols, false);
     }
   }
@@ -1035,17 +1018,14 @@ void grid_del_lines(ScreenGrid *grid, int row, int line_count, int end, int col,
       }
       j -= line_count;
       grid_clear_line(grid, grid->line_offset[j] + (size_t)col, width, false);
-      grid->line_wraps[j] = false;
     } else {
       // whole width, moving the line pointers is faster
       j = row + i;
       temp = (unsigned)grid->line_offset[j];
       while ((j += line_count) <= end - 1) {
         grid->line_offset[j - line_count] = grid->line_offset[j];
-        grid->line_wraps[j - line_count] = grid->line_wraps[j];
       }
       grid->line_offset[j - line_count] = temp;
-      grid->line_wraps[j - line_count] = false;
       grid_clear_line(grid, temp, grid->cols, false);
     }
   }

src/nvim/grid_defs.h

@@ -52,10 +52,6 @@ enum {
 /// line_offset[n] is the offset from chars[], attrs[] and vcols[] for the start
 /// of line 'n'. These offsets are in general not linear, as full screen scrolling
 /// is implemented by rotating the offsets in the line_offset array.
-///
-/// line_wraps[] is an array of boolean flags indicating if the screen line
-/// wraps to the next line. It can only be true if a window occupies the entire
-/// screen width.
 typedef struct ScreenGrid ScreenGrid;
 struct ScreenGrid {
   handle_T handle;
@@ -64,7 +60,6 @@ struct ScreenGrid {
   sattr_T *attrs;
   colnr_T *vcols;
   size_t *line_offset;
-  char *line_wraps;
 
   // last column that was drawn (not cleared with the default background).
   // only used when "throttled" is set. Not allocated by grid_alloc!
@@ -120,7 +115,7 @@ struct ScreenGrid {
   bool comp_disabled;
 };
 
-#define SCREEN_GRID_INIT { 0, NULL, NULL, NULL, NULL, NULL, NULL, 0, 0, false, \
+#define SCREEN_GRID_INIT { 0, NULL, NULL, NULL, NULL, NULL, 0, 0, false, \
                            false, 0, 0, NULL, false, true, 0, \
                            0, 0, 0, 0, 0,  false }
 

src/nvim/ui_compositor.c

@@ -413,9 +413,7 @@ static void compose_line(Integer row, Integer startcol, Integer endcol, LineFlag
   assert(endcol <= chk_width);
   assert(row < chk_height);
 
-  if (!(grid && grid == &default_grid)) {
+  if (!(grid && (grid == &default_grid || (grid->comp_col == 0 && grid->cols == Columns)))) {
-    // TODO(bfredl): too conservative, need check
-    // grid->line_wraps if grid->Width == Width
     flags = flags & ~kLineFlagWrap;
   }