Remove relative units from bounding box

When adding units to the external inset bounding box I overlooked that
InsetGraphics supports only bb, cm, mm and in. Therefore I added too many
units for the external insets. We are not as strict as the graphics inset
and allow all absolute units, but no relative ones.

src/frontends/qt4/GuiExternal.cpp

@@ -220,6 +220,18 @@ GuiExternal::GuiExternal(GuiView & lv)
 
 	// add scale item
 	widthUnitCO->insertItem(0, qt_("Scale%"), "scale");
+
+	// remove all units from bb that depend on font or other dimensions
+	// we cannot use these, since we need to compare against absolute
+	// values from the image file.
+	xlUnitCO->noPercents();
+	xlUnitCO->removeFontDependent();
+	xrUnitCO->noPercents();
+	xrUnitCO->removeFontDependent();
+	ytUnitCO->noPercents();
+	ytUnitCO->removeFontDependent();
+	ybUnitCO->noPercents();
+	ybUnitCO->removeFontDependent();
 }
 
 

src/frontends/qt4/LengthCombo.cpp

@@ -98,6 +98,14 @@ void LengthCombo::noPercents()
 }
 
 
+void LengthCombo::removeFontDependent()
+{
+	removeUnit(Length::EM);
+	removeUnit(Length::EX);
+	removeUnit(Length::MU);
+}
+
+
 void LengthCombo::removeUnit(lyx::Length::UNIT unit)
 {
 	QString const val = lyx::toqstr(lyx::stringFromUnit(unit));

src/frontends/qt4/LengthCombo.h

@@ -41,6 +41,8 @@ public:
 	virtual void setEnabled(bool b);
 	/// use the %-items?
 	void noPercents();
+	/// Remove EM, EX and MU units
+	void removeFontDependent();
 	/// remove a unit from the combo
 	void removeUnit(lyx::Length::UNIT unit);
 	/// add a unit to the combo