From 18c4c9c702d740c1da4d182b34472c84cc48a2ac Mon Sep 17 00:00:00 2001
From: Michael Grant <mgrant@grant.org>
Date: Wed, 7 Oct 2026 14:41:35 +0200
Subject: [PATCH] For the *-output commands like select-output, if cmd had no
 output like "true" then select an empty string.

---
 regress/output-commands.sh | 20 +++++++++++++++++++-
 tmux.1                     |  5 +++--
 window-copy.c              | 31 ++++++-------------------------
 3 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/regress/output-commands.sh b/regress/output-commands.sh
index 8a9af5b37..2233ce753 100755
--- a/regress/output-commands.sh
+++ b/regress/output-commands.sh
@@ -95,9 +95,27 @@ sleep 1
 $TMUX copy-mode -t :empty || exit 1
 $TMUX set-buffer sentinel || exit 1
 $TMUX send-keys -t :empty.0 -X copy-output || exit 1
-[ "$($TMUX show-buffer)" = one ] || exit 1
+[ "$($TMUX show-buffer)" = sentinel ] || exit 1
+$TMUX send-keys -t :empty.0 -X select-output || exit 1
+[ "$($TMUX display-message -p -t :empty.0 '#{selection_present}')" = 0 ] || exit 1
 $TMUX send-keys -t :empty.0 -X cancel || exit 1
 
+$TMUX new-window -d -n emptyprompt "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\033]133;C\\007one\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007true\\n\\033]133;C\\007\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :emptyprompt || exit 1
+$TMUX set-buffer sentinel || exit 1
+$TMUX send-keys -t :emptyprompt.0 -X copy-output || exit 1
+[ "$($TMUX show-buffer)" = sentinel ] || exit 1
+$TMUX send-keys -t :emptyprompt.0 -X cancel || exit 1
+
+$TMUX new-window -d -n blank "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\n\\033]133;C\\007\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
+sleep 1
+$TMUX copy-mode -t :blank || exit 1
+$TMUX set-buffer sentinel || exit 1
+$TMUX send-keys -t :blank.0 -X copy-output || exit 1
+[ $($TMUX show-buffer | wc -c) -eq 1 ] || exit 1
+$TMUX send-keys -t :blank.0 -X cancel || exit 1
+
 $TMUX new-window -d -n prompt "printf '\\033]133;A\\007p\\$ \\033]133;B\\007echo\\033]133;C\\007one\\n\\033]133;D;0\\007\\033]133;A\\007p\\$ \\033]133;B\\007'; exec sleep 100" || exit 1
 sleep 1
 $TMUX copy-mode -t :prompt || exit 1
diff --git a/tmux.1 b/tmux.1
index 895331e72..363ecd283 100644
--- a/tmux.1
+++ b/tmux.1
@@ -2579,11 +2579,12 @@ If there is no
 .Ql D
 marker, the output ends at the last used cell in the copy-mode buffer,
 omitting unused blank rows at the bottom.
-At the following prompt or below it, they use the most recent nonempty output.
+At the following prompt or below it, they use the most recent output.
 With
 .Fl a ,
 they use the entire copy-mode buffer instead.
-If no output range can be found, no text is copied, piped or opened.
+If no output range can be found, or the output is empty, no text is copied,
+piped or opened.
 .Pp
 The search commands come in several varieties:
 .Ql search\-forward
diff --git a/window-copy.c b/window-copy.c
index c4043de96..ff058e329 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -6246,8 +6246,6 @@ window_copy_find_output_range(struct window_mode_entry *wme, u_int *sx,
 	int				 found_start = 0, found_end = 0;
 	int				 next_prompt, in_range, end_ok;
 	int				 found;
-	void				*buf;
-	size_t				 len;
 
 	cursor_x = data->cx;
 	cursor_y = screen_hsize(data->backing) + data->cy - data->oy;
@@ -6332,14 +6330,6 @@ window_copy_find_output_range(struct window_mode_entry *wme, u_int *sx,
 		}
 		window_copy_output_end(data->backing, ex, ey);
 	}
-	buf = window_copy_get_grid_range(wme, *sx, *sy, *ex, *ey, &len);
-	if (buf == NULL) {
-		log_debug("%s: empty output", __func__);
-		found = window_copy_find_previous_output_range(wme, cursor_x,
-		    cursor_y, sx, sy, ex, ey);
-		return (found);
-	}
-	free(buf);
 	log_debug("%s: output from %u,%u to %u,%u", __func__, *sx, *sy,
 	    *ex, *ey);
 	return (1);
@@ -6355,10 +6345,8 @@ window_copy_find_previous_output_range(struct window_mode_entry *wme,
 	struct grid			*gd = data->backing->grid;
 	struct grid_line		*gl;
 	struct osc133_data		*od;
-	void				*buf;
-	u_int				 start_x, start_y, end_x, end_y;
+	u_int				 start_x, start_y;
 	u_int				 y, total;
-	size_t				 len;
 	int				 found = 0, have_prompt = 0;
 	int				 pending = 0;
 	int				 has_start, has_end, end_first;
@@ -6398,18 +6386,11 @@ window_copy_find_previous_output_range(struct window_mode_entry *wme,
 			}
 		}
 		if (pending && has_end) {
-			end_x = od->out_end_col;
-			end_y = y;
-			buf = window_copy_get_grid_range(wme, start_x, start_y,
-			    end_x, end_y, &len);
-			if (buf != NULL) {
-				free(buf);
-				*sx = start_x;
-				*sy = start_y;
-				*ex = end_x;
-				*ey = end_y;
-				found = 1;
-			}
+			*sx = start_x;
+			*sy = start_y;
+			*ex = od->out_end_col;
+			*ey = y;
+			found = 1;
 			pending = 0;
 		}
 		if (has_start && end_first) {