From 4e34bce8db0cb68ac47d4c6a42a8d37361a4dfa7 Mon Sep 17 00:00:00 2001
From: Daniel Mendler <mail@daniel-mendler.de>
Date: Sun, 2 May 2021 16:19:42 +0200
Subject: [PATCH 4/5] (completion--insert-vertical): Separate groups completely

Insert the candidates vertically within the groups, but keep the
groups completely separate using the full width group separators.

* minibuffer.el (completion--insert-vertical): Adjust grouping.
---
 lisp/minibuffer.el | 108 ++++++++++++++++++++-------------------------
 1 file changed, 48 insertions(+), 60 deletions(-)

diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index b743b2bd40..73a38a8137 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1866,66 +1866,54 @@ completion--insert-horizontal
 (defun completion--insert-vertical (strings group-fun
                                             _length _wwidth
                                             colwidth columns)
-  (let ((column 0)
-        (rows (/ (length strings) columns))
-	(row 0)
-	(last-title nil)
-	(last-string nil)
-        (start-point (point))
-        (next 0) (pos 0))
-    (dolist (str strings)
-      (unless (equal last-string str) ; Remove (consecutive) duplicates.
-	(setq last-string str)
-	(when (> row rows)
-	  (goto-char start-point)
-	  (setq row 0 column (+ column colwidth)))
-        (when group-fun
-          (let ((title (funcall group-fun (if (consp str) (car str) str) nil)))
-            (unless (equal title last-title)
-              (setq last-title title)
-              (when title
-                ;; Align before title insertion
-	        (when (> column 0)
-	          (end-of-line)
-	          (while (> (current-column) column)
-	            (if (eobp)
-		        (insert "\n")
-	              (forward-line 1)
-	              (end-of-line)))
-	          (insert " \t")
-	          (set-text-properties (1- (point)) (point)
-			               `(display (space :align-to ,column))))
-                (let* ((fmt completions-group-format)
-                       (len (length fmt)))
-                  ;; Adjust display space for columns
-                  (when (equal (get-text-property (- len 1) 'display fmt) '(space :align-to right))
-                    (setq fmt (substring fmt))
-                    (put-text-property (- len 1) len
-                                       'display
-                                       `(space :align-to ,(+ colwidth column -1))
-                                       fmt))
-                  (insert (format fmt title)))
-                ;; Align after title insertion
-	        (if (> column 0)
-	            (forward-line)
-	          (insert "\n"))))))
-        ;; Align before candidate insertion
-	(when (> column 0)
-	  (end-of-line)
-	  (while (> (current-column) column)
-	    (if (eobp)
-		(insert "\n")
-	      (forward-line 1)
-	      (end-of-line)))
-	  (insert " \t")
-	  (set-text-properties (1- (point)) (point)
-			       `(display (space :align-to ,column))))
-        (completion--insert str group-fun)
-        ;; Align after candidate insertion
-	(if (> column 0)
-	    (forward-line)
-	  (insert "\n"))
-	(setq row (1+ row))))))
+  (while strings
+    (let ((group nil)
+          (column 0)
+	  (row 0)
+          (rows)
+          (last-string nil))
+      (if group-fun
+          (let* ((str (car strings))
+                 (title (funcall group-fun (if (consp str) (car str) str) nil)))
+            (while (and strings
+                        (equal title (funcall group-fun
+                                              (if (consp (car strings))
+                                                  (car (car strings))
+                                                (car strings))
+                                              nil)))
+              (push (car strings) group)
+              (pop strings))
+            (setq group (nreverse group)))
+        (setq group strings
+              strings nil))
+      (setq rows (/ (length group) columns))
+      (when group-fun
+        (let* ((str (car group))
+               (title (funcall group-fun (if (consp str) (car str) str) nil)))
+          (when title
+            (goto-char (point-max))
+            (insert (format completions-group-format title) "\n"))))
+      (dolist (str group)
+        (unless (equal last-string str) ; Remove (consecutive) duplicates.
+	  (setq last-string str)
+	  (when (> row rows)
+            (forward-line (- -1 rows))
+	    (setq row 0 column (+ column colwidth)))
+	  (when (> column 0)
+	    (end-of-line)
+	    (while (> (current-column) column)
+	      (if (eobp)
+		  (insert "\n")
+	        (forward-line 1)
+	        (end-of-line)))
+	    (insert " \t")
+	    (set-text-properties (1- (point)) (point)
+			         `(display (space :align-to ,column))))
+          (completion--insert str group-fun)
+	  (if (> column 0)
+	      (forward-line)
+	    (insert "\n"))
+	  (setq row (1+ row)))))))
 
 (defun completion--insert-one-column (strings group-fun &rest _)
   (let ((last-title nil) (last-string nil))
-- 
2.20.1