From: Hirohito Higashi <h.east.727@gmail.com>
Date: Tue, 11 Aug 2026 19:21:08 +0000 (+0000)
Subject: patch 9.2.0940: GTK4: columns are lost when a scrollbar appears
X-Git-Tag: v9.2.0940^0
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=67eee0fc0d7e680ce0837f088e490c1c43258297;p=thirdparty%2Fvim.git

patch 9.2.0940: GTK4: columns are lost when a scrollbar appears

Problem:  With the GTK4 GUI the shell loses columns every time a window is
          split, so that the text area keeps getting narrower.
Solution: Ignore a size allocation that was computed before the size that
          was last asked for, instead of computing Rows and Columns from
          the old size together with the new base size.

closes: #21006

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
---

diff --git a/src/gui.h b/src/gui.h
index 5be8d0fd9b..280215515b 100644
--- a/src/gui.h
+++ b/src/gui.h
@@ -505,6 +505,13 @@ typedef struct Gui
 #if defined(FEAT_GUI_GTK) && defined(USE_GTK4)
     int decor_height;
 
+    // Size of the form widget last asked for with gui_mch_set_shellsize().
+    // "pending_form_skip" counts how many allocations that do not answer it
+    // may still be ignored.
+    int pending_form_w;
+    int pending_form_h;
+    int pending_form_skip;
+
     // Used for clipboard functionality in GTK4 GUI
     GdkContentProvider *regular_provider;
     GdkContentProvider *primary_provider;
diff --git a/src/gui_gtk4.c b/src/gui_gtk4.c
index c2f2564e6f..d128a6b999 100644
--- a/src/gui_gtk4.c
+++ b/src/gui_gtk4.c
@@ -959,6 +959,13 @@ gui_mch_set_shellsize(int width, int height,
 	int base_width UNUSED, int base_height UNUSED,
 	int direction UNUSED)
 {
+    // Remember the size the form widget is supposed to get. An allocation
+    // that arrives before the compositor has answered this request still has
+    // the previous size and must not be used.
+    gui.pending_form_w = width;
+    gui.pending_form_h = height;
+    gui.pending_form_skip = 1;
+
     width += get_menu_tool_width();
     height += get_menu_tool_height();
 
diff --git a/src/gui_gtk4_f.c b/src/gui_gtk4_f.c
index 195749d2a5..e61092c669 100644
--- a/src/gui_gtk4_f.c
+++ b/src/gui_gtk4_f.c
@@ -216,7 +216,21 @@ vim_form_resize_idle_cb(VimForm *self)
 	goto exit;
 
     if (self->last_width > 1 && self->last_height > 1)
+    {
+	// Ignore an allocation that does not answer the size that was last
+	// asked for: it was computed before the request and using it would
+	// compute Rows and Columns from the old size together with the new
+	// base size, losing columns. Give up after one allocation in case
+	// the request is never answered exactly.
+	if (gui.pending_form_w > 0
+		&& (self->last_width != gui.pending_form_w
+		    || self->last_height != gui.pending_form_h)
+		&& --gui.pending_form_skip >= 0)
+	    goto exit;
+
+	gui.pending_form_w = 0;
 	gui_resize_shell(self->last_width, self->last_height);
+    }
 
 exit:
     g_object_unref(self);
diff --git a/src/version.c b/src/version.c
index 6405f229e6..5ea5c96e22 100644
--- a/src/version.c
+++ b/src/version.c
@@ -763,6 +763,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    940,
 /**/
     939,
 /**/