From 273f9b2027e395b9256af96d211e87023b1c5801 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Wed, 20 Nov 2024 20:54:02 +0000
Subject: [PATCH] Fix word navigation on lines with tabs, from Alexander Arch.

---
 grid-reader.c | 17 +++++++----------
 grid.c        | 24 ++++++++++++++++++++++++
 tmux.h        |  3 ++-
 window-copy.c |  6 +-----
 4 files changed, 34 insertions(+), 16 deletions(-)

diff --git a/grid-reader.c b/grid-reader.c
index 6cd60c50..be374cd7 100644
--- a/grid-reader.c
+++ b/grid-reader.c
@@ -180,19 +180,14 @@ grid_reader_handle_wrap(struct grid_reader *gr, u_int *xx, u_int *yy)
 int
 grid_reader_in_set(struct grid_reader *gr, const char *set)
 {
-	struct grid_cell	gc;
-
-	grid_get_cell(gr->gd, gr->cx, gr->cy, &gc);
-	if (gc.flags & GRID_FLAG_PADDING)
-		return (0);
-	return (utf8_cstrhas(set, &gc.data));
+	return (grid_in_set(gr->gd, gr->cx, gr->cy, set));
 }
 
 /* Move cursor to the start of the next word. */
 void
 grid_reader_cursor_next_word(struct grid_reader *gr, const char *separators)
 {
-	u_int	xx, yy;
+	u_int	xx, yy, width;
 
 	/* Do not break up wrapped words. */
 	if (grid_get_line(gr->gd, gr->cy)->flags & GRID_LINE_WRAPPED)
@@ -229,8 +224,8 @@ grid_reader_cursor_next_word(struct grid_reader *gr, const char *separators)
 		}
 	}
 	while (grid_reader_handle_wrap(gr, &xx, &yy) &&
-	    grid_reader_in_set(gr, WHITESPACE))
-		gr->cx++;
+	    (width = grid_reader_in_set(gr, WHITESPACE)))
+		gr->cx += width;
 }
 
 /* Move cursor to the end of the next word. */
@@ -425,7 +420,9 @@ grid_reader_cursor_back_to_indentation(struct grid_reader *gr)
 		xx = grid_line_length(gr->gd, py);
 		for (px = 0; px < xx; px++) {
 			grid_get_cell(gr->gd, px, py, &gc);
-			if (gc.data.size != 1 || *gc.data.data != ' ') {
+			if ((gc.data.size != 1 || *gc.data.data != ' ') &&
+			    ~gc.flags & GRID_FLAG_TAB &&
+			    ~gc.flags & GRID_FLAG_PADDING) {
 				gr->cx = px;
 				gr->cy = py;
 				return;
diff --git a/grid.c b/grid.c
index 53002a67..0098c81c 100644
--- a/grid.c
+++ b/grid.c
@@ -1561,3 +1561,27 @@ grid_line_length(struct grid *gd, u_int py)
 	}
 	return (px);
 }
+
+/* Check if character is in set. */
+int
+grid_in_set(struct grid *gd, u_int px, u_int py, const char *set)
+{
+	struct grid_cell	gc, tmp_gc;
+	u_int			pxx;
+
+	grid_get_cell(gd, px, py, &gc);
+	if (strchr(set, '\t')) {
+		if (gc.flags & GRID_FLAG_PADDING) {
+			pxx = px;
+			do
+				grid_get_cell(gd, --pxx, py, &tmp_gc);
+			while (pxx > 0 && tmp_gc.flags & GRID_FLAG_PADDING);
+			if (tmp_gc.flags & GRID_FLAG_TAB)
+				return (tmp_gc.data.width - (px - pxx));
+		} else if (gc.flags & GRID_FLAG_TAB)
+			return (gc.data.width);
+	}
+	if (gc.flags & GRID_FLAG_PADDING)
+		return (0);
+	return (utf8_cstrhas(set, &gc.data));
+}
diff --git a/tmux.h b/tmux.h
index ae25c5a9..066c3821 100644
--- a/tmux.h
+++ b/tmux.h
@@ -605,7 +605,7 @@ enum tty_code_code {
 };
 
 /* Character classes. */
-#define WHITESPACE " "
+#define WHITESPACE "\t "
 
 /* Mode keys. */
 #define MODEKEY_EMACS 0
@@ -2944,6 +2944,7 @@ void	 grid_reflow(struct grid *, u_int);
 void	 grid_wrap_position(struct grid *, u_int, u_int, u_int *, u_int *);
 void	 grid_unwrap_position(struct grid *, u_int *, u_int *, u_int, u_int);
 u_int	 grid_line_length(struct grid *, u_int);
+int	 grid_in_set(struct grid *, u_int, u_int, const char *);
 
 /* grid-reader.c */
 void	 grid_reader_start(struct grid_reader *, struct grid *, u_int, u_int);
diff --git a/window-copy.c b/window-copy.c
index 0d705629..36b9f89c 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -5033,12 +5033,8 @@ window_copy_in_set(struct window_mode_entry *wme, u_int px, u_int py,
     const char *set)
 {
 	struct window_copy_mode_data	*data = wme->data;
-	struct grid_cell		 gc;
 
-	grid_get_cell(data->backing->grid, px, py, &gc);
-	if (gc.flags & GRID_FLAG_PADDING)
-		return (0);
-	return (utf8_cstrhas(set, &gc.data));
+	return (grid_in_set(data->backing->grid, px, py, set));
 }
 
 static u_int