Using a custom path for Source Folder Selection

[tpecar]

Currently the Default option assumes the path to be relative to the executable running the test,
which, in case of Eclipse CDT, is the current build configuration output folder (usually Debug / Release).

Given that CDT compiles relative to the output folder, the unit tests with main also report relative to the output folder, example

#beginning MySuite 1
#starting fails_this_test
#failure fails_this_test ../my-unit-test.c:12 Expected [0 == 1] to [be true]
#ending MySuite

For such case everything runs out of the box.

Again, knowing fully that I'm using the plugin outside of its scope, I have a use case where the actual executable
(in my case, cgreen-runner, which runs the unit tests compiled as shared libraries) resides outside the location of the compiled unit test.

Trying to set a custom source folder, as provided in the launch configuration

causes the plugin to emit NullPointerException when trying to open the souce file, stack trace shown below.
This happens with a C project, with or without CUTE and/or C++ project nature.

!ENTRY org.eclipse.jface 4 2 2022-11-11 11:34:28.412
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.jface".
!STACK 0
java.lang.NullPointerException
	at ch.hsr.ifs.testframework.ui.CuteTestDClickListener.doubleClick(CuteTestDClickListener.kt:68)
	at org.eclipse.jface.viewers.StructuredViewer$1.run(StructuredViewer.java:780)
	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:174)
	at org.eclipse.jface.viewers.StructuredViewer.fireDoubleClick(StructuredViewer.java:777)
	at org.eclipse.jface.viewers.AbstractTreeViewer.handleDoubleSelect(AbstractTreeViewer.java:1529)
	at org.eclipse.jface.viewers.StructuredViewer$4.widgetDefaultSelected(StructuredViewer.java:1211)
	at org.eclipse.jface.util.OpenStrategy.fireDefaultSelectionEvent(OpenStrategy.java:272)
	at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:329)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:89)
	at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4243)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1060)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4060)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3632)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1154)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1045)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:644)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:551)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:156)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:136)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:659)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:596)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1467)