master 9c2cbfa49db: Fix Python indentation of continuation lines within parens

[Eli Zaretskii]

branch: master
commit 9c2cbfa49db96eae95bb40c5fc3ce7f09781a97d
Author: kobarity <kobarity@gmail.com>
Commit: Eli Zaretskii <eliz@gnu.org>

    Fix Python indentation of continuation lines within parens
    
    * lisp/progmodes/python.el (python-indent-context): Add a new indent
    context `:inside-paren-continuation-line'.
    (python-indent--calculate-indentation): Use the new indent context.
    * test/lisp/progmodes/python-tests.el (python-indent-pep8-2)
    (python-indent-pep8-3)
    (python-indent-inside-paren-1)
    (python-indent-inside-paren-2)
    (python-indent-inside-paren-3)
    (python-indent-inside-paren-6)
    (python-indent-after-backslash-2): Change to use the new indent
    context.
    (python-indent-inside-paren-8)
    (python-indent-inside-paren-9): New tests. (Bug#63959)
---
 lisp/progmodes/python.el            | 26 ++++++++++-
 test/lisp/progmodes/python-tests.el | 89 ++++++++++++++++++++++++++++++++-----
 2 files changed, 101 insertions(+), 14 deletions(-)

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 26dafde7591..50d712ebb0c 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1406,6 +1406,10 @@ keyword
  - Point is inside a paren from a block start followed by some
    items on the same line.
  - START is the first non space char position *after* the open paren.
+:inside-paren-continuation-line
+ - Point is on a continuation line inside a paren.
+ - START is the position where the previous line (excluding lines
+   for inner parens) starts.
 
 :after-backslash
  - Fallback case when point is after backslash.
@@ -1460,7 +1464,21 @@ keyword
                      (= (line-number-at-pos)
                         (progn
                           (python-util-forward-comment)
-                          (line-number-at-pos))))))))
+                          (line-number-at-pos)))))))
+               (continuation-start
+                (when start
+                  (save-excursion
+                    (forward-line -1)
+                    (back-to-indentation)
+                    ;; Skip inner parens.
+                    (cl-loop with prev-start = (python-syntax-context 'paren)
+                             while (and prev-start (>= prev-start start))
+                             if (= prev-start start)
+                             return (point)
+                             else do (goto-char prev-start)
+                                     (back-to-indentation)
+                                     (setq prev-start
+                                           (python-syntax-context 'paren)))))))
           (when start
             (cond
              ;; Current line only holds the closing paren.
@@ -1476,6 +1494,9 @@ keyword
                 (back-to-indentation)
                 (python-syntax-closing-paren-p))
               (cons :inside-paren-at-closing-nested-paren start))
+             ;; This line is a continuation of the previous line.
+             (continuation-start
+              (cons :inside-paren-continuation-line continuation-start))
              ;; This line starts from an opening block in its own line.
              ((save-excursion
                 (goto-char start)
@@ -1591,7 +1612,8 @@ possibilities can be narrowed to specific indentation 
points."
         (`(,(or :after-line
                 :after-comment
                 :inside-string
-                :after-backslash) . ,start)
+                :after-backslash
+                :inside-paren-continuation-line) . ,start)
          ;; Copy previous indentation.
          (goto-char start)
          (current-indentation))
diff --git a/test/lisp/progmodes/python-tests.el 
b/test/lisp/progmodes/python-tests.el
index 9323f72f384..54e32cbf07b 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -683,7 +683,7 @@ def long_function_name(
    (should (= (python-indent-calculate-indentation) 8))
    (python-tests-look-at "var_four):")
    (should (eq (car (python-indent-context))
-               :inside-paren-newline-start-from-block))
+               :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 8))
    (python-tests-look-at "print (var_one)")
    (should (eq (car (python-indent-context))
@@ -707,8 +707,8 @@ foo = long_function_name(
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))
    (should (= (python-indent-calculate-indentation) 4))
    (python-tests-look-at "var_three, var_four)")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
-   (should (= (python-indent-calculate-indentation) 4))))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
+   (should (= (python-indent-calculate-indentation) 2))))
 
 (ert-deftest python-indent-hanging-close-paren ()
   "Like first pep8 case, but with hanging close paren." ;; See Bug#20742.
@@ -864,7 +864,7 @@ data = {
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))
    (should (= (python-indent-calculate-indentation) 4))
    (python-tests-look-at "{")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 4))
    (python-tests-look-at "'objlist': [")
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))
@@ -876,20 +876,20 @@ data = {
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))
    (should (= (python-indent-calculate-indentation) 16))
    (python-tests-look-at "'name': 'first',")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 16))
    (python-tests-look-at "},")
    (should (eq (car (python-indent-context))
                :inside-paren-at-closing-nested-paren))
    (should (= (python-indent-calculate-indentation) 12))
    (python-tests-look-at "{")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 12))
    (python-tests-look-at "'pk': 2,")
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))
    (should (= (python-indent-calculate-indentation) 16))
    (python-tests-look-at "'name': 'second',")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 16))
    (python-tests-look-at "}")
    (should (eq (car (python-indent-context))
@@ -933,7 +933,7 @@ data = {'key': {
    (should (eq (car (python-indent-context)) :inside-paren))
    (should (= (python-indent-calculate-indentation) 9))
    (python-tests-look-at "{'pk': 2,")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 8))
    (python-tests-look-at "'name': 'second'}")
    (should (eq (car (python-indent-context)) :inside-paren))
@@ -966,10 +966,10 @@ data = ('these',
    (should (eq (car (python-indent-context)) :inside-paren))
    (should (= (python-indent-calculate-indentation) 8))
    (forward-line 1)
-   (should (eq (car (python-indent-context)) :inside-paren))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 8))
    (forward-line 1)
-   (should (eq (car (python-indent-context)) :inside-paren))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 8))))
 
 (ert-deftest python-indent-inside-paren-4 ()
@@ -1023,7 +1023,7 @@ CHOICES = (('some', 'choice'),
    (should (eq (car (python-indent-context)) :inside-paren))
    (should (= (python-indent-calculate-indentation) 11))
    (forward-line 1)
-   (should (eq (car (python-indent-context)) :inside-paren))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 11))))
 
 (ert-deftest python-indent-inside-paren-7 ()
@@ -1034,6 +1034,71 @@ CHOICES = (('some', 'choice'),
    ;; This signals an error if the test fails
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))))
 
+(ert-deftest python-indent-inside-paren-8 ()
+  "Test for Bug#63959."
+  (python-tests-with-temp-buffer
+   "
+for a in [  # comment
+          'some',  # Manually indented.
+          'thing']:  # Respect indentation of the previous line.
+"
+   (python-tests-look-at "for a in [  # comment")
+   (should (eq (car (python-indent-context)) :no-indent))
+   (should (= (python-indent-calculate-indentation) 0))
+   (forward-line 1)
+   (should (eq (car (python-indent-context))
+               :inside-paren-newline-start-from-block))
+   (should (= (python-indent-calculate-indentation) 8))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
+   (should (= (python-indent-calculate-indentation) 10))))
+
+(ert-deftest python-indent-inside-paren-9 ()
+  "Test `:inside-paren-continuation-line'."
+  (python-tests-with-temp-buffer
+   "
+a = (((
+    1, 2),
+      3),  # Do not respect the indentation of the previous line
+     4)  # Do not respect the indentation of the previous line
+b = ((
+        1, 2),  # Manually indented
+     3,  # Do not respect the indentation of the previous line
+     4,  # Respect the indentation of the previous line
+        5,  # Manually indented
+        6)  # Respect the indentation of the previous line
+"
+   (python-tests-look-at "a = (((")
+   (should (eq (car (python-indent-context)) :no-indent))
+   (should (= (python-indent-calculate-indentation) 0))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (= (python-indent-calculate-indentation) 4))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren))
+   (should (= (python-indent-calculate-indentation) 6))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren))
+   (should (= (python-indent-calculate-indentation) 5))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :after-line))
+   (should (= (python-indent-calculate-indentation) 0))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (= (python-indent-calculate-indentation) 4))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren))
+   (should (= (python-indent-calculate-indentation) 5))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
+   (should (= (python-indent-calculate-indentation) 5))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
+   (should (= (python-indent-calculate-indentation) 5))
+   (forward-line 1)
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
+   (should (= (python-indent-calculate-indentation) 8))))
+
 (ert-deftest python-indent-inside-paren-block-1 ()
   "`python-indent-block-paren-deeper' set to nil (default).
 See Bug#62696."
@@ -1271,7 +1336,7 @@ objects = Thing.objects.all() \\
    (should (eq (car (python-indent-context)) :inside-paren-newline-start))
    (should (= (python-indent-calculate-indentation) 27))
    (python-tests-look-at "status='bought'")
-   (should (eq (car (python-indent-context)) :inside-paren-newline-start))
+   (should (eq (car (python-indent-context)) :inside-paren-continuation-line))
    (should (= (python-indent-calculate-indentation) 27))
    (python-tests-look-at ") \\")
    (should (eq (car (python-indent-context)) :inside-paren-at-closing-paren))