Add completion-auto-select second-tab value.

* lisp/minibuffer.el (completion--in-region-1) : Change if with cond and
check if completion-auto-select.
* lisp/simple.el (completion-auto-select) : Move before first use.
(completion-setup-function) : Make a more precise check for when
completion-auto-select is t.

1 files changed, 19 insertions, 11 deletions

diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index c4fb1c00391..742d39f2d29 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1410,18 +1410,26 @@ scroll the window of possible completions."
    ;; and this command is repeated, scroll that window.
    ((and (window-live-p minibuffer-scroll-window)
          (eq t (frame-visible-p (window-frame minibuffer-scroll-window))))
-    (let ((window minibuffer-scroll-window)
-          (reverse (equal (this-command-keys) [backtab])))
+    (let ((window minibuffer-scroll-window))
       (with-current-buffer (window-buffer window)
-        (if (pos-visible-in-window-p (if reverse (point-min) (point-max)) window)
-            ;; If end or beginning is in view, scroll up to the
-            ;; beginning or end respectively.
-            (if reverse
-                (set-window-point window (point-max))
-              (set-window-start window (point-min) nil))
-          ;; Else scroll down one screen.
-          (with-selected-window window
-            (if reverse (scroll-down) (scroll-up))))
+        (cond
+         ;; here this is possible only when second-tab, so jump now.
+         (completion-auto-select
+          (switch-to-completions))
+         ;; reverse tab
+         ((equal (this-command-keys) [backtab])
+          (if (pos-visible-in-window-p (point-min) window)
+              ;; If beginning is in view, scroll up to the end
+              (set-window-point window (point-max))
+            ;; Else scroll down one screen.
+            (with-selected-window window (scroll-down))))
+         ;; normal tab
+         (t
+          (if (pos-visible-in-window-p (point-max) window)
+              ;; If end is in view, scroll up to the end
+              (set-window-start window (point-min) nil)
+            ;; Else scroll down one screen.
+            (with-selected-window window (scroll-up)))))
         nil)))
    ;; If we're cycling, keep on cycling.
    ((and completion-cycling completion-all-sorted-completions)