From 5615023023aea50683f5725284fb9bc6cbbd64ec Mon Sep 17 00:00:00 2001
From: Taylor R Campbell <campbell+paredit@mumble.net>
Date: Thu, 24 Nov 2022 19:05:29 +0000
Subject: Work around Electric Indent Mode brokenness in newline keys.

---
 NEWS       |  1 +
 paredit.el | 41 ++++++++++++++++++++++++++++++++++++++++-
 test.el    | 32 +++++++++++++++++++++++++-------
 3 files changed, 66 insertions(+), 8 deletions(-)

diff --git a/NEWS b/NEWS
index 765f903..efc6c4e 100644
--- a/NEWS
+++ b/NEWS
@@ -22,6 +22,7 @@ The latest version of this file is available at
 *** Reading character in Backslash escape now inherits input method.
 *** M-r (paredit-raise-sexp) no longer reindents single-line sexps.
 *** Various bug fixes and additions to test suite.
+*** Worked around brokenness induced by Electric Indent Mode.
 
 ** Version 24
 
diff --git a/paredit.el b/paredit.el
index b67b1bd..be45288 100644
--- a/paredit.el
+++ b/paredit.el
@@ -337,11 +337,13 @@ Paredit behaves badly if parentheses are unbalanced, so exercise
                 ("|(defun hello-world ...)"
                  ";;; |\n(defun hello-world ...)"))
 
-   ("C-j"       paredit-newline
+   (()          paredit-newline
                 ("(let ((n (frobbotz))) |(display (+ n 1)\nport))"
                  ,(concat "(let ((n (frobbotz)))"
                           "\n  |(display (+ n 1)"
                           "\n           port))")))
+   ("RET"       paredit-RET)
+   ("C-j"       paredit-C-j)
 
    "Deleting & Killing"
    (("C-d" ,@paredit-forward-delete-keys)
@@ -1007,6 +1009,43 @@ If in a comment and if followed by invalid structure, call
          ;; Indent the following S-expression, but don't signal an
          ;; error if there's only a closing delimiter after the point.
          (paredit-ignore-sexp-errors (indent-sexp)))))
+
+(defun paredit-electric-indent-mode-p ()
+  "True if Electric Indent Mode is on, false if not.
+Electric Indent Mode is generally not compatible with paredit and
+  users are advised to disable it, since paredit does essentially
+  everything it tries to do better.
+However, to mitigate the negative user experience of combining
+ Electric Indent Mode with paredit, the default key bindings for
+ RET and C-j in paredit are exchanged depending on whether
+ Electric Indent Mode is enabled."
+  (and (boundp 'electric-indent-mode)
+       electric-indent-mode))
+
+(defun paredit-RET ()
+  "Default key binding for RET in Paredit Mode.
+Normally, inserts a newline, like traditional Emacs RET.
+With Electric Indent Mode enabled, inserts a newline and indents
+  the new line, as well as any subexpressions of it on subsequent
+  lines."
+  (interactive)
+  (if (paredit-electric-indent-mode-p)
+      (let ((electric-indent-mode nil))
+        (paredit-newline))
+    (newline)))
+
+(defun paredit-C-j ()
+  "Default key binding for C-j in Paredit Mode.
+Normally, inserts a newline and indents
+  the new line, as well as any subexpressions of it on subsequent
+  lines.
+With Electric Indent Mode enabled, inserts a newline, like
+  traditional Emacs RET."
+  (interactive)
+  (if (paredit-electric-indent-mode-p)
+      (let ((electric-indent-mode nil))
+        (newline))
+    (paredit-newline)))
 
 (defun paredit-reindent-defun (&optional argument)
   "Reindent the definition that the point is on.
diff --git a/test.el b/test.el
index bd8ae37..8e6ebe9 100644
--- a/test.el
+++ b/test.el
@@ -220,13 +220,31 @@ Four arguments: the paredit command, the text of the buffer
   (paredit-test 'paredit-wrap-sexp
     '(("(foo |bar baz)" "(foo (|bar baz))"))))
 
-(paredit-test 'paredit-newline
-  '(("\"foo|bar\"" "\"foo\n|bar\"")
-    ("(frob grovel ;full |(lexical)\n      mumble)"
-     "(frob grovel ;full\n      |(lexical)\n      mumble)")
-    ("(frob grovel ;full (|lexical)\n      mumble)"
-     "(frob grovel ;full (\n             ;|lexical)\n      mumble)")
-    ("#\\|(" "#\\(\n|")))
+(let ((plain-newline-tests
+       '(("\"foo|bar\"" "\"foo\n|bar\"")
+         ("(frob grovel ;full |(lexical)\n      mumble)"
+          "(frob grovel ;full \n|(lexical)\n      mumble)")
+         ("(frob grovel ;full (|lexical)\n      mumble)"
+          "(frob grovel ;full (\n|lexical)\n      mumble)")
+         ("#\\|(" "#\\\n|(")))
+      (indented-newline-tests
+       '(("\"foo|bar\"" "\"foo\n|bar\"")
+         ("(frob grovel ;full |(lexical)\n      mumble)"
+          "(frob grovel ;full\n      |(lexical)\n      mumble)")
+         ("(frob grovel ;full (|lexical)\n      mumble)"
+          "(frob grovel ;full (\n             ;|lexical)\n      mumble)")
+         ("#\\|(" "#\\(\n|"))))
+  (if (boundp 'electric-indent-mode)
+      (progn
+        (let ((electric-indent-mode t))
+          (paredit-test 'paredit-RET indented-newline-tests)
+          (paredit-test 'paredit-C-j plain-newline-tests))
+        (let ((electric-indent-mode nil))
+          (paredit-test 'paredit-RET plain-newline-tests)
+          (paredit-test 'paredit-C-j indented-newline-tests)))
+    (paredit-test 'paredit-RET plain-newline-tests)
+    (paredit-test 'paredit-C-j indented-newline-tests))
+  (paredit-test 'paredit-newline indented-newline-tests))
 
 (paredit-test 'paredit-reindent-defun
   ;++ Test filling paragraphs in comments and strings.
-- 
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