Add rounded border tests.

regress/options-values.sh

@@ -86,6 +86,11 @@ check_value "-gv status-keys" "vi"
 check_fail "unknown value: bogus" set -g status-keys bogus
 check_value "-gv status-keys" "vi"
 
+# pane-border-lines accepts rounded as a pane border style.
+check_ok set -gw pane-border-lines rounded
+check_value "-gwv pane-border-lines" "rounded"
+check_ok set -gw pane-border-lines single
+
 # --- flag options ---------------------------------------------------------
 #
 # focus-events is an on/off flag.  Setting with no value toggles it; explicit

regress/screen-redraw-floating.sh

@@ -107,6 +107,12 @@ $TMUX2 new-pane -x28 -y8 -X4 -Y1 -B double \
 	"sh -c 'printf FLOAT; exec sleep 100'" || exit 1
 compare floating-border-double
 
+# Larger floating pane with rounded border lines.
+new_scene 40 12
+$TMUX2 new-pane -x28 -y8 -X4 -Y1 -B rounded \
+	"sh -c 'printf FLOAT; exec sleep 100'" || exit 1
+compare floating-border-rounded
+
 # Floating pane with no border lines: redraw_mark_pane_borders returns early so
 # the float has no border at all, only its (clipped) content over the base pane.
 new_scene 40 12

regress/screen-redraw-results/floating-border-rounded.result

@@ -0,0 +1,12 @@
+base
+    ╭──────────────────────────╮
+    │FLOAT                     │
+    │                          │
+    │                          │
+    │                          │
+    │                          │
+    │                          │
+    ╰──────────────────────────╯
+
+
+