Re: gnus-search-engine set to gnus-search-notmuch and refer threads

[Eric Abrahamsen <eric@ericabrahamsen.net>]

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"Jose A. Ortega Ruiz" <jao@gnu.org> writes:

> On Wed, Dec 22 2021, Eric Abrahamsen wrote:
>
> [...]
>
>> My guess is that we need to go to point-min right here.
>>
>>> 	  (while (re-search-forward "^thread:\\([^ ]+\\)" (point-max) t)
>>> 	    (push (match-string 1) thread-ids))
>>> 	  (cl-call-next-method
>>> 	   engine server
>>> 	   ;; Completely replace the query with our new thread-based one.
>>> 	   (mapconcat (lambda (thrd) (concat "thread:" thrd))
>>> 		      thread-ids " or ")
>>> 	   nil)))
>>>     (cl-call-next-method engine server query groups)))
>
> it's not enough.  before that, there's a problem with invoking the
> search for threads, because notmuch is passed the flag --duplicate=1,
> and that's not accepted for format thread:
>
>   Error: --duplicate=N is only supported with --output=files and --output=messages.
>
> funny thing is that that flag is added for no apparent reason in line
> 1633 of gnus-search.el:
>
>  	"--duplicate=1" ; I have found this necessary, I don't know why.
>
> i don't know why either because searches seem to work without it :).
> if one eliminates that flag and adds your suggested (goto-char
> (point-min)) we are not out the woods yet: the thread id is read, but
> including an eol, so one needs
>
>   (while (re-search-forward "^thread:\\([^\n ]+\\)" (point-max) t)
>                                          ^^^^
>
> and then, we still fail, because that leads, somehow to an error of the
> form:
>
>   Debugger entered--Lisp error: (wrong-type-argument listp "thread:000000000001a830")
>      alist-get(parsed-query "thread:000000000001a830")
>      #f(compiled-function (engine query-spec) #<bytecode 0x1fd1b560df8c2360>)(#<gnus-search-notmuch gnus-search-notmuch-157d5a02af62> "thread:000000000001a830")
>      apply(#f(compiled-function (engine query-spec) #<bytecode 0x1fd1b560df8c2360>) #<gnus-search-notmuch gnus-search-notmuch-157d5a02af62> "thread:000000000001a830")
>      gnus-search-make-query-string(#<gnus-search-notmuch gnus-search-notmuch-157d5a02af62> "thread:000000000001a830")
>
> which indicates that the notmuch method for
> gnus-search-make-query-string is buggy: it doesn't know how to parse
> "thread:000000000001a830" queries...  and here i ran out of steam, but
> the fix seems nearby :)

Here's what I've got so far, would you try it out? I'm not sure about
notmuch not knowing how to parse a "thread:000000000001a830" query, it
looks like it handles it fine to me:

(let* ((engine (make-instance 'gnus-search-notmuch))
       (query "thread:23434223455")
       (parsed-query (gnus-search-parse-query query)))
  (gnus-search-make-query-string engine `((query ,query)
					  (parsed-query . ,parsed-query))))

=> "thread:23434223455"

Am I misunderstanding something?


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diff --git a/lisp/gnus/gnus-search.el b/lisp/gnus/gnus-search.el
index d64c0cb90c..bb7fd47eb6 100644
--- a/lisp/gnus/gnus-search.el
+++ b/lisp/gnus/gnus-search.el
@@ -1606,13 +1606,17 @@ gnus-search-run-search
 			    proc-buffer program cp-list))
 	  (while (process-live-p proc)
 	    (accept-process-output proc))
-	  (while (re-search-forward "^thread:\\([^ ]+\\)" (point-max) t)
-	    (push (match-string 1) thread-ids))
+          (goto-char (point-min))
+	  (while (re-search-forward "^thread:\\([^[:space:]\n]+\\)" (point-max) t)
+	    (cl-pushnew (match-string 1) thread-ids :test #'equal))
 	  (cl-call-next-method
 	   engine server
-	   ;; Completely replace the query with our new thread-based one.
-	   (mapconcat (lambda (thrd) (concat "thread:" thrd))
-		      thread-ids " or ")
+	   ;; If we found threads, completely replace the query with
+	   ;; our new thread-based one.
+           (if thread-ids
+	       (mapconcat (lambda (thrd) (concat "thread:" thrd))
+		          thread-ids " or ")
+             query)
 	   nil)))
     (cl-call-next-method engine server query groups)))
 
@@ -1629,8 +1633,9 @@ gnus-search-indexed-search-command
 	"search"
 	,(if thread
 	     "--output=threads"
-	   "--output=files")
-	"--duplicate=1" ; I have found this necessary, I don't know why.
+           ;; No one knows why this "duplicate" flag is necessary, but
+           ;; it doesn't work with a thread search.
+	   "--output=files --duplicate=1")
 	,@switches
 	,(if limit (format "--limit=%d" limit) "")
 	,qstring