gp-import: fixed arpeggio duration for gp4 files

Backport of musescore#24581

importexport/guitarpro/importgtp-gp4.cpp

@@ -12,47 +12,46 @@
 
 #include "importgtp.h"
 
-#include <libmscore/score.h>
-#include <libmscore/measurebase.h>
-#include <libmscore/text.h>
+#include <libmscore/arpeggio.h>
+#include <libmscore/articulation.h>
+#include <libmscore/barline.h>
+#include <libmscore/bend.h>
+#include <libmscore/bracket.h>
 #include <libmscore/box.h>
-#include <libmscore/staff.h>
-#include <libmscore/part.h>
-#include <libmscore/measure.h>
-#include <libmscore/timesig.h>
-#include <libmscore/tremolo.h>
-#include <libmscore/chordline.h>
-#include <libmscore/glissando.h>
-#include <libmscore/rest.h>
 #include <libmscore/chord.h>
-#include <libmscore/note.h>
-#include <libmscore/stringdata.h>
+#include <libmscore/chordline.h>
 #include <libmscore/clef.h>
-#include <libmscore/lyrics.h>
-#include <libmscore/tempotext.h>
-#include <libmscore/slur.h>
-#include <libmscore/tie.h>
-#include <libmscore/tuplet.h>
-#include <libmscore/barline.h>
+#include <libmscore/dynamic.h>
 #include <libmscore/excerpt.h>
-#include <libmscore/stafftype.h>
-#include <libmscore/bracket.h>
-#include <libmscore/articulation.h>
-#include <libmscore/keysig.h>
+#include <libmscore/fingering.h>
+#include <libmscore/glissando.h>
 #include <libmscore/harmony.h>
-#include <libmscore/bend.h>
-#include <libmscore/tremolobar.h>
-#include <libmscore/segment.h>
-#include <libmscore/rehearsalmark.h>
-#include <libmscore/dynamic.h>
-#include <libmscore/arpeggio.h>
-#include <libmscore/volta.h>
 #include <libmscore/instrtemplate.h>
-#include <libmscore/fingering.h>
+#include <libmscore/keysig.h>
+#include <libmscore/lyrics.h>
+#include <libmscore/measure.h>
+#include <libmscore/measurebase.h>
+#include <libmscore/note.h>
 #include <libmscore/notedot.h>
+#include <libmscore/part.h>
+#include <libmscore/rehearsalmark.h>
+#include <libmscore/rest.h>
+#include <libmscore/score.h>
+#include <libmscore/segment.h>
+#include <libmscore/slur.h>
+#include <libmscore/staff.h>
 #include <libmscore/stafftext.h>
+#include <libmscore/stafftype.h>
+#include <libmscore/stringdata.h>
 #include <libmscore/sym.h>
-#include <libmscore/instrtemplate.h>
+#include <libmscore/tempotext.h>
+#include <libmscore/text.h>
+#include <libmscore/tie.h>
+#include <libmscore/timesig.h>
+#include <libmscore/tremolo.h>
+#include <libmscore/tremolobar.h>
+#include <libmscore/tuplet.h>
+#include <libmscore/volta.h>
 
 namespace Ms {
 
@@ -125,9 +124,13 @@ int GuitarPro4::readBeatEffects(int track, Segment* segment)
             Arpeggio* a = new Arpeggio(score);
             if( strokeup > 0 ) {
                   a->setArpeggioType(ArpeggioType::UP_STRAIGHT);
+                  if (strokeup < 7)
+                        a->setStretch(1.0 / std::pow(2, 6 - strokeup));
                   }
             else if( strokedown > 0 ) {
                   a->setArpeggioType(ArpeggioType::DOWN_STRAIGHT);
+                  if (strokedown < 7)
+                        a->setStretch(1.0 / std::pow(2, 6 - strokedown));
                   }
             else {
                   delete a;