Prevent null pointer deference in methods for selection.

This resolves the crash when exporting the Basket archive.

Signed-off-by: Slávek Banko <slavek.banko@axis.cz>
(cherry picked from commit a08c6ac9e3c8ac162ce08b730fd6108e2f71213c)

1 files changed, 12 insertions, 0 deletions

diff --git a/src/basket.cpp b/src/basket.cpp
index a4edb31..67107d2 100644
--- a/src/basket.cpp
+++ b/src/basket.cpp
@@ -4469,12 +4469,20 @@ void Basket::noteUngroup()
 
 void Basket::unplugSelection(NoteSelection *selection)
 {
+	if (!selection)
+	{
+		return;
+	}
 	for (NoteSelection *toUnplug = selection->firstStacked(); toUnplug; toUnplug = toUnplug->nextStacked())
 		unplugNote(toUnplug->note);
 }
 
 void Basket::insertSelection(NoteSelection *selection, Note *after)
 {
+	if (!selection)
+	{
+		return;
+	}
 	for (NoteSelection *toUnplug = selection->firstStacked(); toUnplug; toUnplug = toUnplug->nextStacked()) {
 		if (toUnplug->note->isGroup()) {
 			Note *group = new Note(this);
@@ -4496,6 +4504,10 @@ void Basket::insertSelection(NoteSelection *selection, Note *after)
 
 void Basket::selectSelection(NoteSelection *selection)
 {
+	if (!selection)
+	{
+		return;
+	}
 	for (NoteSelection *toUnplug = selection->firstStacked(); toUnplug; toUnplug = toUnplug->nextStacked()) {
 		if (toUnplug->note->isGroup())
 			selectSelection(toUnplug);