Subject: Re: bug#60505: 29.0.60; Fido Mode and Tramp Completion

From: Gregory Heytings <[email-masked]>
Date: Fri, 06 Jan 2023 09:51:11 +0000

>
> Why could we not use the ad-hoc patch, with a FIXME note, until somebody 
> has the time to find a better solution, instead of letting bug reports 
> about that problem accumulate?  Sure, it could possibly have a 
> collateral damage, but it could as well have no collateral damage at 
> all.
>

By the way, to limit the scope of the potential collateral damages, it is 
also possible to use that condition only when completion-styles contain 
'substring' or 'flex'.

What do you think of the attached patch?
From efe26b4dc2693619cc3d569c5da9dd2a43323044 Mon Sep 17 00:00:00 2001
From: Gregory Heytings <[email-masked]>
Date: Fri, 6 Jan 2023 09:48:02 +0000
Subject: [PATCH] Improve handling of non-default completion styles with Tramp
 methods

* lisp/net/tramp.el
(tramp-completion-handle-file-name-all-completions): Do not return
Tramp methods when the filename already contains a complete method
and completion-styles contain 'substring' and/or 'flex'.

* lisp/icomplete.el (icomplete--fido-mode-setup): Add 'basic'
after 'flex' in the completion styles, for cases where 'flex' does
not return anything.  This is required by Tramp.

* doc/misc/tramp.texi (File name completion): Remove the footnote
about the limitation of the 'substring' and 'flex' completion
styles.

Fixes bug#50387, bug#51386, bug#52758, bug#53513, bug#54042 and
bug#60505.
---
 doc/misc/tramp.texi |  5 +----
 lisp/icomplete.el   |  3 ++-
 lisp/net/tramp.el   | 13 +++++++++++--
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi
index 56436d3297..c43d9a9991 100644
--- a/doc/misc/tramp.texi
+++ b/doc/misc/tramp.texi
@@ -3497,10 +3497,7 @@ File name completion
 Type @kbd{s h @value{postfixhop}} for the minibuffer completion to
 @samp{@value{prefix}ssh@value{postfixhop}}.  Typing @kbd{@key{TAB}}
 shows host names @value{tramp} extracts from @file{~/.ssh/config}
-@c bug#50387
-file, for example@footnote{Some completion styles, like
-@code{substring} or @code{flex}, require to type at least one
-character after the trailing @samp{@value{postfixhop}}.}.
+file, for example.
 
 @example
 @group
diff --git a/lisp/icomplete.el b/lisp/icomplete.el
index 9fa622017f..e91c2f254a 100644
--- a/lisp/icomplete.el
+++ b/lisp/icomplete.el
@@ -414,7 +414,8 @@ icomplete--fido-mode-setup
                 icomplete-show-matches-on-no-input t
                 icomplete-hide-common-prefix nil
                 icomplete-scroll (not (null icomplete-vertical-mode))
-                completion-styles '(flex)
+                ;; The 'basic' style is required by Tramp.
+                completion-styles '(flex basic)
                 completion-flex-nospace nil
                 completion-ignore-case t
                 read-buffer-completion-ignore-case t
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index f0b17ef393..8e0b0e9c6e 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3022,8 +3022,17 @@ tramp-completion-handle-file-name-all-completions
 			       (delq nil all-user-hosts)))))
 
 	    ;; Possible methods.
-	    (setq result
-		  (append result (tramp-get-completion-methods m)))))))
+	    ;; FIXME: This is a workaround to handle the substring and
+	    ;; flex completion styles in a better way, until a better
+	    ;; fix to handle Tramp methods, possibly in the code of
+	    ;; these completion styles, is implemented.  See
+	    ;; bug#50387, bug#51386, bug#52758, bug#53513, bug#54042
+	    ;; and bug#60505.
+	    (unless (and (string-empty-p method)
+			 (or (memq 'substring completion-styles)
+			     (memq 'flex completion-styles)))
+	      (setq result
+		    (append result (tramp-get-completion-methods m))))))))
 
     ;; Unify list, add hop, remove nil elements.
     (dolist (elt result)
-- 
2.39.0