master 4d656ea: Don't send empty lines for implicit targets in ERC

[Lars Ingebrigtsen]

branch: master
commit 4d656ea5ff7ba79315af42e159254867bfd157ad
Author: F. Jason Park <jp@neverwas.me>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Don't send empty lines for implicit targets in ERC
    
    * erc.el (erc-send-input-line): Previously, any line typed into a
    query or channel buffer without an explicit user-command
    handler (meaning most lines), would be sent twice because a trailing
    newline (linefeed) would be appended. This has been verified by
    checking IRCd server logs. IRCds won't return an error upon receiving
    an empty message, but they also won't forward them to channel
    subscribers and DM pals.
    
    * erc-tests.el: Add test for erc-process-input-line, which also
    indirectly tests erc-send-input-line. It also tests the command
    lookup and dispatch facility (bug#50008).
---
 lisp/erc/erc.el            | 21 +++++++---------
 test/lisp/erc/erc-tests.el | 62 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+), 12 deletions(-)

diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 88c1050..0da8370 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -2817,20 +2817,17 @@ present."
   (let ((prop-val (erc-get-parsed-vector position)))
     (and prop-val (member (erc-response.command prop-val) list))))
 
-(defvar-local erc-send-input-line-function 'erc-send-input-line)
+(defvar-local erc-send-input-line-function 'erc-send-input-line
+  "Function for sending lines lacking a leading user command.
+When a line typed into a buffer contains an explicit command, like /msg,
+a corresponding handler (here, erc-cmd-MSG) is called.  But lines typed
+into a channel or query buffer already have an implicit target and
+command (PRIVMSG).  This function is called on such occasions and also
+for special purposes (see erc-dcc.el).")
 
 (defun erc-send-input-line (target line &optional force)
-  "Send LINE to TARGET.
-
-See also `erc-server-send'."
-  (setq line (format "PRIVMSG %s :%s"
-                     target
-                     ;; If the line is empty, we still want to
-                     ;; send it - i.e. an empty pasted line.
-                     (if (string= line "\n")
-                         " \n"
-                       line)))
-  (erc-server-send line force target))
+  "Send LINE to TARGET."
+  (erc-message "PRIVMSG" (concat target " " line) force))
 
 (defun erc-get-arglist (fun)
   "Return the argument list of a function without the parens."
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 6ed26f6..685f4e2 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -228,4 +228,66 @@
     (kill-buffer "*erc-protocol*")
     (should-not erc-debug-irc-protocol)))
 
+
+;; The point of this test is to ensure output is handled identically
+;; regardless of whether a command handler is summoned.
+
+(ert-deftest erc-process-input-line ()
+  (let (erc-server-last-sent-time
+        erc-server-flood-queue
+        (orig-erc-cmd-MSG (symbol-function 'erc-cmd-MSG))
+        calls)
+    (with-temp-buffer
+      (cl-letf (((symbol-function 'erc-cmd-MSG)
+                 (lambda (line)
+                   (push line calls)
+                   (funcall orig-erc-cmd-MSG line)))
+                ((symbol-function 'erc-server-buffer)
+                 (lambda () (current-buffer)))
+                ((symbol-function 'erc-server-process-alive)
+                 (lambda () t))
+                ((symbol-function 'erc-server-send-queue)
+                 #'ignore)
+                ((symbol-function 'erc-default-target)
+                 (lambda () "" "#chan")))
+
+        (ert-info ("Dispatch to user command handler")
+
+          (ert-info ("Baseline")
+            (erc-process-input-line "/msg #chan hi\n")
+            (should (equal (pop calls) " #chan hi"))
+            (should (equal (pop erc-server-flood-queue)
+                           '("PRIVMSG #chan :hi\r\n" . utf-8))))
+
+          (ert-info ("Spaces preserved")
+            (erc-process-input-line "/msg #chan hi you\n")
+            (should (equal (pop calls) " #chan hi you"))
+            (should (equal (pop erc-server-flood-queue)
+                           '("PRIVMSG #chan :hi you\r\n" . utf-8))))
+
+          (ert-info ("Empty line honored")
+            (erc-process-input-line "/msg #chan\n")
+            (should (equal (pop calls) " #chan"))
+            (should (equal (pop erc-server-flood-queue)
+                           '("PRIVMSG #chan :\r\n" . utf-8)))))
+
+        (ert-info ("Implicit cmd via `erc-send-input-line-function'")
+
+          (ert-info ("Baseline")
+            (erc-process-input-line "hi")
+            (should (equal (pop erc-server-flood-queue)
+                           '("PRIVMSG #chan :hi\r\n" . utf-8))))
+
+          (ert-info ("Spaces preserved")
+            (erc-process-input-line "hi you")
+            (should (equal (pop erc-server-flood-queue)
+                           '("PRIVMSG #chan :hi you\r\n" . utf-8))))
+
+          (ert-info ("Empty line transmitted without injected-space kludge")
+            (erc-process-input-line "")
+            (should (equal (pop erc-server-flood-queue)
+                           '("PRIVMSG #chan :\r\n" . utf-8))))
+
+          (should-not calls))))))
+
 ;;; erc-tests.el ends here