BUGFIX: Fixed crash on some include file cases.

Reported by ETH students last year: if you include a file, where the file has an
error in a line with a number higher than the original, the Python code crashes.

This is a *patch* only because the real underlying problem is that error reporting
does not take include commands into account, and does not propagate any
file names.

gui/Gui/Editor.py

@@ -158,7 +158,21 @@ class EditorStc(Editor):
     def SetText(self, txt):
         self.control.SetText(txt)
 
+    def GetLineCount(self):
+        """ Currently rather stupid, can probably be done more
+        efficiently through some Scintilla function. """
+        txt = self.GetText().splitlines()
+        return len(txt)
+
     def SetErrorLine(self,line):
+        """
+        Currently this is BROKEN for include commands, as no file names
+        are propagated. To minize the damage, we at least don't try to
+        highlight non-existing names. In the long run of course
+        propagation is the only way to handle this.
+        """
+        if line <= self.GetLineCount():
+            if line > 0:
                 line = line - 1     # Start at 0 in stc, but on screen count is 1
                 pos = self.control.GetLineIndentPosition(line)
                 last = self.control.GetLineEndPosition(line)