Fix an issue with focus lost after closing terminal panel

Summary:
After leaving terminal with Ctrl-D or exit commands the input focus isn't set back to the folder view.
The problem appears, because `TerminalPanel::isHiddenInVisibleWindow` returns not what it supposed to return,
since when the terminal process exits, `m_terminal` is set to nullptr.

I moved unwanted checks from it inside `TerminalPanel::dockVisibilityChanged`

This change also exposes a crash in `DolphinMainWindow::slotTerminalPanelVisibilityChanged()`,
which was previously working only by luck.
Now we check whether `m_activeViewContainer` is not null before using it.

BUG: 407979
FIXED-IN: 19.11.80

Test Plan:
1. Open Dolphin
2. Press F4 to open the terminal panel
3. Type exit<Enter> or press Ctrl-D
4. Check current focus widget

Reviewers: #dolphin

Subscribers: ngraham, elvisangelaccio, kfm-devel

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D22420

1 files changed, 2 insertions, 4 deletions

diff --git a/src/panels/terminal/terminalpanel.cpp b/src/panels/terminal/terminalpanel.cpp
index 52d2a77df..86974d200 100644
--- a/src/panels/terminal/terminalpanel.cpp
+++ b/src/panels/terminal/terminalpanel.cpp
@@ -82,16 +82,14 @@ void TerminalPanel::terminalExited()
 bool TerminalPanel::isHiddenInVisibleWindow() const
 {
     return parentWidget()
-        && parentWidget()->isHidden()
-        && m_terminal
-        && !hasProgramRunning();
+        && parentWidget()->isHidden();
 }
 
 void TerminalPanel::dockVisibilityChanged()
 {
     // Only react when the DockWidget itself (not some parent) is hidden. This way we don't
     // respond when e.g. Dolphin is minimized.
-    if (isHiddenInVisibleWindow()) {
+    if (isHiddenInVisibleWindow() && m_terminal && !hasProgramRunning()) {
         // Make sure that the following "cd /" command will not affect the view.
         disconnect(m_konsolePart, SIGNAL(currentDirectoryChanged(QString)),
                    this, SLOT(slotKonsolePartCurrentDirectoryChanged(QString)));