From 66b5477cc1909e57489f854939a524ce2cd0f479 Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Mon, 10 Oct 2016 17:28:30 +0000
Subject: [PATCH] Do not allow the opposite pane to resize when dragging with
 the mouse because it is not possible to keep the mouse on the border when the
 minimum size is reached.

---
 cmd-resize-pane.c | 12 ++++++------
 layout.c          | 20 +++++++++++---------
 tmux.h            |  2 +-
 3 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/cmd-resize-pane.c b/cmd-resize-pane.c
index 7ec65f10..fa52ab14 100644
--- a/cmd-resize-pane.c
+++ b/cmd-resize-pane.c
@@ -111,13 +111,13 @@ cmd_resize_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 	}
 
 	if (args_has(self->args, 'L'))
-		layout_resize_pane(wp, LAYOUT_LEFTRIGHT, -adjust);
+		layout_resize_pane(wp, LAYOUT_LEFTRIGHT, -adjust, 1);
 	else if (args_has(self->args, 'R'))
-		layout_resize_pane(wp, LAYOUT_LEFTRIGHT, adjust);
+		layout_resize_pane(wp, LAYOUT_LEFTRIGHT, adjust, 1);
 	else if (args_has(self->args, 'U'))
-		layout_resize_pane(wp, LAYOUT_TOPBOTTOM, -adjust);
+		layout_resize_pane(wp, LAYOUT_TOPBOTTOM, -adjust, 1);
 	else if (args_has(self->args, 'D'))
-		layout_resize_pane(wp, LAYOUT_TOPBOTTOM, adjust);
+		layout_resize_pane(wp, LAYOUT_TOPBOTTOM, adjust, 1);
 	server_redraw_window(wl->window);
 
 	return (CMD_RETURN_NORMAL);
@@ -155,12 +155,12 @@ cmd_resize_pane_mouse_update(struct client *c, struct mouse_event *m)
 
 		if (wp->xoff + wp->sx == m->lx &&
 		    wp->yoff <= 1 + ly && wp->yoff + wp->sy >= ly) {
-			layout_resize_pane(wp, LAYOUT_LEFTRIGHT, m->x - m->lx);
+			layout_resize_pane(wp, LAYOUT_LEFTRIGHT, m->x - m->lx, 0);
 			found = 1;
 		}
 		if (wp->yoff + wp->sy == ly &&
 		    wp->xoff <= 1 + m->lx && wp->xoff + wp->sx >= m->lx) {
-			layout_resize_pane(wp, LAYOUT_TOPBOTTOM, y - ly);
+			layout_resize_pane(wp, LAYOUT_TOPBOTTOM, y - ly, 0);
 			found = 1;
 		}
 	}
diff --git a/layout.c b/layout.c
index dffa08bd..490dbf0b 100644
--- a/layout.c
+++ b/layout.c
@@ -36,7 +36,7 @@
 static u_int	layout_resize_check(struct window *, struct layout_cell *,
 		    enum layout_type);
 static int	layout_resize_pane_grow(struct window *, struct layout_cell *,
-		    enum layout_type, int);
+		    enum layout_type, int, int);
 static int	layout_resize_pane_shrink(struct window *, struct layout_cell *,
 		    enum layout_type, int);
 static int	layout_need_status(struct layout_cell *, int);
@@ -532,12 +532,13 @@ layout_resize_pane_to(struct window_pane *wp, enum layout_type type,
 		change = new_size - size;
 
 	/* Resize the pane. */
-	layout_resize_pane(wp, type, change);
+	layout_resize_pane(wp, type, change, 1);
 }
 
 /* Resize a single pane within the layout. */
 void
-layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
+layout_resize_pane(struct window_pane *wp, enum layout_type type, int change,
+    int opposite)
 {
 	struct window		*w = wp->window;
 	struct layout_cell	*lc, *lcparent;
@@ -562,7 +563,8 @@ layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
 	needed = change;
 	while (needed != 0) {
 		if (change > 0) {
-			size = layout_resize_pane_grow(w, lc, type, needed);
+			size = layout_resize_pane_grow(w, lc, type, needed,
+			    opposite);
 			needed -= size;
 		} else {
 			size = layout_resize_pane_shrink(w, lc, type, needed);
@@ -582,10 +584,10 @@ layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
 /* Helper function to grow pane. */
 static int
 layout_resize_pane_grow(struct window *w, struct layout_cell *lc,
-    enum layout_type type, int needed)
+    enum layout_type type, int needed, int opposite)
 {
 	struct layout_cell	*lcadd, *lcremove;
-	u_int			 size;
+	u_int			 size = 0;
 
 	/* Growing. Always add to the current cell. */
 	lcadd = lc;
@@ -600,7 +602,7 @@ layout_resize_pane_grow(struct window *w, struct layout_cell *lc,
 	}
 
 	/* If none found, look towards the head. */
-	if (lcremove == NULL) {
+	if (opposite && lcremove == NULL) {
 		lcremove = TAILQ_PREV(lc, layout_cells, entry);
 		while (lcremove != NULL) {
 			size = layout_resize_check(w, lcremove, type);
@@ -608,9 +610,9 @@ layout_resize_pane_grow(struct window *w, struct layout_cell *lc,
 				break;
 			lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
 		}
-		if (lcremove == NULL)
-			return (0);
 	}
+	if (lcremove == NULL)
+		return (0);
 
 	/* Change the cells. */
 	if (size > (u_int) needed)
diff --git a/tmux.h b/tmux.h
index 1789ec2c..21802854 100644
--- a/tmux.h
+++ b/tmux.h
@@ -2217,7 +2217,7 @@ void		 layout_init(struct window *, struct window_pane *);
 void		 layout_free(struct window *);
 void		 layout_resize(struct window *, u_int, u_int);
 void		 layout_resize_pane(struct window_pane *, enum layout_type,
-		     int);
+		     int, int);
 void		 layout_resize_pane_to(struct window_pane *, enum layout_type,
 		     u_int);
 void		 layout_assign_pane(struct layout_cell *, struct window_pane *);