Fix #17548 Allow melisma to be deleted (or adjusted) on chordrest duration change or lyric entry

src/engraving/layout/v0/lyricslayout.cpp

@@ -135,7 +135,8 @@ void LyricsLayout::layout(Lyrics* item, LayoutContext& ctx)
     ChordRest* cr = item->chordRest();
     if (item->_removeInvalidSegments) {
         item->removeInvalidSegments();
-    } else if (item->_ticks > Fraction(0, 1) || item->_syllabic == LyricsSyllabic::BEGIN || item->_syllabic == LyricsSyllabic::MIDDLE) {
+    }
+    if (item->_ticks > Fraction(0, 1) || item->_syllabic == LyricsSyllabic::BEGIN || item->_syllabic == LyricsSyllabic::MIDDLE) {
         if (!item->_separator) {
             item->_separator = new LyricsLine(ctx.mutDom().dummyParent());
             item->_separator->setTick(cr->tick());
@@ -279,13 +280,15 @@ void LyricsLayout::layout(LyricsLine* item, LayoutContext& ctx)
                 ps = ps->prev1(SegmentType::ChordRest);
             }
             if (!ps || ps == lyricsSegment) {
-                // no valid previous CR, so try to lengthen melisma instead
+                // either there is no valid previous CR, or the previous CR is the one the lyric starts on
+                // we don't want to make the melisma longer arbitrarily, but there is a possibility that the next
+                // CR won't extend the melisma, so let's check it
                 ps = ns;
                 s = ps->nextCR(lyricsTrack, true);
                 EngravingItem* e = s ? s->element(lyricsTrack) : nullptr;
                 // check to make sure we have a chord
-                if (!e || e->type() != ElementType::CHORD) {
-                    // nothing to do but set ticks to 0
+                if (!e || e->type() != ElementType::CHORD || ps->tick() > item->tick() + item->ticks()) {
+                    // nope, nothing to do but set ticks to 0
                     // this will result in melisma being deleted later
                     item->lyrics()->undoChangeProperty(Pid::LYRIC_TICKS, Fraction::fromTicks(0));
                     item->setTicks(Fraction(0, 1));

src/engraving/layout/v0/tlayout.cpp

@@ -5327,6 +5327,9 @@ SpannerSegment* TLayout::layoutSystemSLine(SLine* line, System* system, LayoutCo
 
 SpannerSegment* TLayout::layoutSystem(LyricsLine* line, System* system, LayoutContext& ctx)
 {
+    if (!line->lyrics()) {
+        return nullptr; // a lyrics line with no lyrics shouldn't exist
+    }
     Fraction stick = system->firstMeasure()->tick();
     Fraction etick = system->lastMeasure()->endTick();
 
@@ -5402,7 +5405,10 @@ SpannerSegment* TLayout::layoutSystem(LyricsLine* line, System* system, LayoutCo
     }
 
     TLayout::layout(lineSegm, ctx);
-
+    if (!line->lyrics()) {
+        // this line could have been removed in the process of laying out surrounding lyrics
+        return nullptr;
+    }
     // if temp melisma extend the first line segment to be
     // after the lyrics syllable (otherwise the melisma segment
     // will be too short).

src/engraving/libmscore/line.cpp

@@ -886,7 +886,7 @@ PointF SLine::linePos(Grip grip, System** sys) const
                         }
                     }
                 }
-            } else if (isLyricsLine() && toLyrics(explicitParent())->ticks() > Fraction(0, 1)) {
+            } else if (isLyricsLine() && explicitParent() && toLyrics(explicitParent())->ticks() > Fraction(0, 1)) {
                 // melisma line
                 // it is possible CR won't be in correct track
                 // prefer element in current track if available

src/engraving/libmscore/lyrics.cpp

@@ -313,13 +313,37 @@ bool Lyrics::isEditAllowed(EditData& ed) const
     return TextBase::isEditAllowed(ed);
 }
 
+void Lyrics::adjustPrevious()
+{
+    Lyrics* prev = prevLyrics(toLyrics(this));
+    if (prev) {
+        // search for lyric spanners to split at this point if necessary
+        if (prev->tick() + prev->ticks() >= tick()) {
+            // the previous lyric has a spanner attached that goes through this one
+            // we need to shorten it
+            Segment* s = score()->tick2segment(tick());
+            if (s) {
+                s = s->prev1(SegmentType::ChordRest);
+                if (s->tick() > prev->tick()) {
+                    prev->undoChangeProperty(Pid::LYRIC_TICKS, s->tick() - prev->tick());
+                } else {
+                    prev->undoChangeProperty(Pid::LYRIC_TICKS, Fraction::fromTicks(1));
+                }
+            }
+        }
+        prev->setRemoveInvalidSegments();
+        prev->triggerLayout();
+    }
+}
+
 //---------------------------------------------------------
 //   endEdit
 //---------------------------------------------------------
 
 void Lyrics::endEdit(EditData& ed)
 {
     TextBase::endEdit(ed);
+
     triggerLayoutAll();
 }
 
@@ -373,6 +397,9 @@ PropertyValue Lyrics::getProperty(Pid propertyId) const
 
 bool Lyrics::setProperty(Pid propertyId, const PropertyValue& v)
 {
+    ChordRest* scr = nullptr;
+    ChordRest* ecr = nullptr;
+
     switch (propertyId) {
     case Pid::PLACEMENT:
         setPlacement(v.value<PlacementV>());
@@ -389,14 +416,14 @@ bool Lyrics::setProperty(Pid propertyId, const PropertyValue& v)
             // endTick info is wrong.
             // Somehow we need to fix this.
             // See https://musescore.org/en/node/285304 and https://musescore.org/en/node/311289
-            ChordRest* ecr = score()->findCR(endTick(), track());
+            ecr = score()->findCR(endTick(), track());
             if (ecr) {
                 ecr->setMelismaEnd(false);
             }
         }
-
+        scr = score()->findCR(tick(), track());
         _ticks = v.value<Fraction>();
-        if (_ticks <= Fraction(0, 1)) {
+        if (scr && _ticks <= scr->ticks()) {
             // if no ticks, we have to relayout in order to remove invalid melisma segments
             setRemoveInvalidSegments();
             layout()->layoutItem(this);
@@ -520,8 +547,8 @@ void Lyrics::removeInvalidSegments()
     _removeInvalidSegments = false;
     if (_separator && isMelisma() && _ticks < _separator->startCR()->ticks()) {
         setTicks(Fraction(0, 1));
+        _separator->setTicks(Fraction(0, 1));
         _separator->removeUnmanaged();
-        delete _separator;
         _separator = nullptr;
         setAlign(propertyDefault(Pid::ALIGN).value<Align>());
         if (_syllabic == LyricsSyllabic::BEGIN || _syllabic == LyricsSyllabic::SINGLE) {

src/engraving/libmscore/lyrics.h

@@ -88,6 +88,7 @@ class Lyrics final : public TextBase
     Fraction endTick() const;
     void removeFromScore();
     void setRemoveInvalidSegments() { _removeInvalidSegments = true; }
+    void adjustPrevious();
 
     using EngravingObject::undoChangeProperty;
     void paste(EditData& ed, const String& txt) override;
@@ -141,7 +142,7 @@ class LyricsLine final : public SLine
 
     Lyrics* lyrics() const { return toLyrics(explicitParent()); }
     Lyrics* nextLyrics() const { return _nextLyrics; }
-    bool isEndMelisma() const { return lyrics()->ticks().isNotZero(); }
+    bool isEndMelisma() const { return lyrics() && lyrics()->ticks().isNotZero(); }
     bool isDash() const { return !isEndMelisma(); }
     bool setProperty(Pid propertyId, const PropertyValue& v) override;
 

src/engraving/libmscore/textedit.cpp

@@ -222,6 +222,11 @@ void TextBase::endEdit(EditData& ed)
     } else {
         triggerLayout();
     }
+    if (isLyrics()) {
+        // we must adjust previous lyrics before the call to commitText(), in order to make the adjustments
+        // part of the same undo command. there is logic above that will skip this call if the text is empty
+        toLyrics(this)->adjustPrevious();
+    }
 
     static const double w = 2.0;
     score()->addRefresh(canvasBoundingRect().adjusted(-w, -w, w, w));