From 4a2ffc83f8c1cff1e03b86d4f4824c23631624df Mon Sep 17 00:00:00 2001
From: Bernhard Roider <bernhard.roider@sonnenkinder.org>
Date: Wed, 9 May 2007 20:09:03 +0000
Subject: [PATCH] Problem: A crash when no color is selected and the "alter"
 button is pressed. Solution: Disable the alter button if no item is selected
 and add an additional test for a valid index.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@18247 a592a061-630c-0410-9148-cb99ea01b6c8
---
 src/frontends/qt4/QPrefs.cpp | 14 +++++++++++++-
 src/frontends/qt4/QPrefs.h   |  1 +
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/frontends/qt4/QPrefs.cpp b/src/frontends/qt4/QPrefs.cpp
index cbc9a373c0..8566d7868b 100644
--- a/src/frontends/qt4/QPrefs.cpp
+++ b/src/frontends/qt4/QPrefs.cpp
@@ -545,6 +545,8 @@ PrefColors::PrefColors(QPrefs * form, QWidget * parent)
 
 	connect(colorChangePB, SIGNAL(clicked()),
 		this, SLOT(change_color()));
+	connect(lyxObjectsLW, SIGNAL(itemSelectionChanged()),
+		this, SLOT(change_lyxObjects_selection()));
 	connect(lyxObjectsLW, SIGNAL(itemActivated(QListWidgetItem*)),
 		this, SLOT(change_color()));
 }
@@ -570,12 +572,17 @@ void PrefColors::apply(LyXRC & /*rc*/) const
 // problem here.
 void PrefColors::update(LyXRC const & /*rc*/)
 {
+	change_lyxObjects_selection();
 }
 
 void PrefColors::change_color()
 {
 	int const row = lyxObjectsLW->currentRow();
-	QString color = newcolors_[row];
+
+	// just to be sure
+	if (row < 0) return;
+
+	QString const color = newcolors_[row];
 	QColor c(QColorDialog::getColor(QColor(color), qApp->focusWidget()));
 
 	if (c.isValid() && c.name() != color) {
@@ -588,6 +595,11 @@ void PrefColors::change_color()
 	}
 }
 
+void PrefColors::change_lyxObjects_selection()
+{
+	colorChangePB->setDisabled(lyxObjectsLW->currentRow() < 0);
+}
+
 
 /////////////////////////////////////////////////////////////////////
 //
diff --git a/src/frontends/qt4/QPrefs.h b/src/frontends/qt4/QPrefs.h
index 6efdcadbdc..0757813e9e 100644
--- a/src/frontends/qt4/QPrefs.h
+++ b/src/frontends/qt4/QPrefs.h
@@ -156,6 +156,7 @@ public:
 
 private Q_SLOTS:
 	void change_color();
+	void change_lyxObjects_selection();
 
 private:
 	std::vector<Color_color> lcolors_;