From 2b1e4fd89d57bfecd23afbdeb55293792398f826 Mon Sep 17 00:00:00 2001
From: David Kastrup <dak@gnu.org>
Date: Sun, 31 May 2015 10:53:57 +0200
Subject: [PATCH] Issue 4426: Remove bar checks at the end of \parallelMusic
 passages

This allows ending \parallelMusic at non-bar boundaries.
---
 input/regression/parallelmusic-partial.ly | 34 +++++++++++++++++++++++
 ly/music-functions-init.ly                | 23 ++++++++++++---
 2 files changed, 53 insertions(+), 4 deletions(-)
 create mode 100644 input/regression/parallelmusic-partial.ly

diff --git a/input/regression/parallelmusic-partial.ly b/input/regression/parallelmusic-partial.ly
new file mode 100644
index 0000000000..1ae05af13b
--- /dev/null
+++ b/input/regression/parallelmusic-partial.ly
@@ -0,0 +1,34 @@
+\version "2.19.22"
+
+\header {
+  texidoc = "
+@code{\\parallelMusic} does not complain about incomplete bars at its
+end.
+"
+}
+
+\parallelMusic vI.vII
+\fixed c'
+{
+  f2 |
+  a2 |
+  d2 r2 |
+  d2 r8 cis cis cis |
+  d4 r4 \bar "|." |
+  d4 r4 \bar "|." |
+}
+
+global =
+{
+  \key d\minor
+  \time 4/4
+  \partial 2
+}
+
+\score {
+  \new StaffGroup
+  <<
+    \new Staff { \global \vI }
+    \new Staff { \global \vII }
+  >>
+}
diff --git a/ly/music-functions-init.ly b/ly/music-functions-init.ly
index 0dfb92a1c0..6e9e627eec 100644
--- a/ly/music-functions-init.ly
+++ b/ly/music-functions-init.ly
@@ -1030,6 +1030,9 @@ Example:
   B = { d d | e e | }
   C = { e e | f f | }
 @end verbatim
+
+The last bar checks in a sequence are not copied to the result in
+order to facilitate ending the last entry at non-bar boundaries.
 ")
    (define voice-count (length voice-ids))
    (define (bar-check? m)
@@ -1050,7 +1053,7 @@ Example:
              "Store the previously built sequence into the current voice and
 change to the following voice."
              (set-car! current-voices
-                       (cons (reverse! current-sequence)
+                       (cons current-sequence
                              (car current-voices)))
              (set! current-sequence '())
              (set! current-voices (cdr current-voices)))
@@ -1067,9 +1070,21 @@ change to the following voice."
                                (if (bar-check? m) (change-voice))))))
                      lst)
            (if (pair? current-sequence) (change-voice))
-           ;; un-circularize `voices' and reorder the voices
-           (set! voices (map reverse!
-                             (list-head voices voice-count)))
+           ;; Un-circularize voices
+           (set! voices (list-head voices voice-count))
+
+           ;; Remove trailing bar checks to facilitate ending a
+           ;; sequence on a non-bar, reverse partial sequences and sequences
+           (set! voices (map!
+                         (lambda (l)
+                           (map! reverse!
+                                 (reverse!
+                                  (if (and (pair? l) (pair? (car l))
+                                           (bar-check? (caar l)))
+                                      (cons (cdar l) (cdr l))
+                                      l))))
+                         voices))
+
            ;; check sequence length
            (apply for-each (lambda seqs
                              (define (seq-len seq)
-- 
2.39.5