shell panes follow new pty output only in tty mode: normal/insert hold the scrolled view even when the pane isn't active (the old gate only protected the active pane; tag edits use the remembered body mode). New ttyfollow.snap: background job streams into a scrolled-up normal-mode pane without moving it, tty mode follows again.

3 files changed, 146 insertions, 3 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index 8fb0b43d..f647ed00 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -939,9 +939,12 @@ pub const Pardes = struct {
                 const pane = p.panes[o.pane] orelse return;
                 pane.tty_stream.appendSlice(p.gpa, o.bytes) catch {};
                 pane.stream.nextSlice(o.bytes);
-                // follow new output to the bottom — except in the pane being
-                // actively navigated in a text mode.
-                if (!(o.pane == p.active and pane.mode != .tty))
+                // follow new output to the bottom only in tty mode; in
+                // normal/insert the user is reading scrollback and the view
+                // holds still while output streams in. Tag edits hijack
+                // pane.mode to insert — the body mode sits in tag_mode.
+                const bmode = if (pane.tag_edit) pane.tag_mode else pane.mode;
+                if (bmode == .tty)
                     pane.vt.screens.active.scroll(.active);
             },
             .eof => |e| p.removePane(e.pane),
diff --git a/test/snapshots/ttyfollow.golden b/test/snapshots/ttyfollow.golden
new file mode 100644
index 00000000..6142159f
--- /dev/null
+++ b/test/snapshots/ttyfollow.golden
@@ -0,0 +1,93 @@
+== snap held-pre grid=100x30 cursor=4,15
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/ttyfollow/cwd Del            NOR /tmp/pardes-snap/ttyfollow/cwd Del
+|  185
+|  186                                               s.txt
+|  187
+|  188
+|  189
+|  190
+|  191
+|  192
+|  193
+|  194
+|  195
+|  196
+|  197
+|  198
+|  NOR /tmp/pardes-snap/ttyfollow/cwd Del
+|
+|  s.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+== snap held-post grid=100x30 cursor=54,7
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/ttyfollow/cwd Del            TTY /tmp/pardes-snap/ttyfollow/cwd Del
+|  185                                               $ ls
+|  186                                               s.txt
+|  187                                               $ touch go; until test -f done1; do sleep 0.05;
+|  188                                               done; echo SYN''CED
+|  189                                               SYNCED
+|  190                                               $
+|  191
+|  192
+|  193
+|  194
+|  195
+|  196
+|  197
+|  198
+|  NOR /tmp/pardes-snap/ttyfollow/cwd Del
+|
+|  s.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+== snap tty-follows grid=100x30 cursor=4,15
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  TTY /tmp/pardes-snap/ttyfollow/cwd Del            TTY /tmp/pardes-snap/ttyfollow/cwd Del
+|  288                                               $ ls
+|  289                                               s.txt
+|  290                                               $ touch go; until test -f done1; do sleep 0.05;
+|  291                                               done; echo SYN''CED
+|  292                                               SYNCED
+|  293                                               $
+|  294
+|  295
+|  296
+|  297
+|  298
+|  299
+|  300
+|  $
+|  NOR /tmp/pardes-snap/ttyfollow/cwd Del
+|
+|  s.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
diff --git a/test/snapshots/ttyfollow.snap b/test/snapshots/ttyfollow.snap
new file mode 100644
index 00000000..e7303b4b
--- /dev/null
+++ b/test/snapshots/ttyfollow.snap
@@ -0,0 +1,47 @@
+# follow-output gate: a shell pane in normal/insert mode holds its scrolled-up
+# view while new pty output streams in (before: only the ACTIVE pane held);
+# back in tty mode output follows to the bottom again. Pane A parks a
+# background job blocked on file `go`, pane B triggers it and syncs on `done1`.
+file s.txt x
+start 30 100 -n 3
+wait 8000 s.txt
+stable 700 20000
+key c-b
+stable 600 8000
+text (until test -f go; do sleep 0.05; done; seq 201 260; touch done1) &
+key enter
+stable 500 8000
+text seq 1 200
+key enter
+wait 8000 199
+stable 700 15000
+key c-b
+stable 600 8000
+wheel up 10 8
+wheel up 10 8
+wheel up 10 8
+stable 500 8000
+snap held-pre
+# focus pane B (right column), trigger A's job, sync on completion: A is now a
+# NON-active normal-mode pane receiving output — its view must not move
+press left 60 5
+release left 60 5
+stable 400 5000
+key c-b
+stable 600 8000
+text touch go; until test -f done1; do sleep 0.05; done; echo SYN''CED
+key enter
+wait 8000 SYNCED
+stable 700 15000
+snap held-post
+# back in A, re-enter tty: the echoed keystrokes pull the view to the bottom
+press left 10 8
+release left 10 8
+stable 400 5000
+key c-b
+stable 600 8000
+text seq 261 300
+key enter
+wait 8000 300
+stable 700 15000
+snap tty-follows