MT: Fix segfault after repository category fetch

At the end of calculating components to install or uninstall, the
check states of the components are updated in the model.

The updateComponentInstallActions() asks both installer and uninstaller
calculators for resolved components, but these may not be valid after
new repository categories are fetched, and the component model is reset.
This would result in dereferencing invalid Component pointers in some
cases. The root cause was that the other calculator was not quaranteed
to be cleared when another requested updating the check states.

Fix by clearing both calculators before full recalculation occurs. Also
clear the calculators when the component environment is reset, for
correctness and to avoid bumping into the similar issue elsewhere in
the code.

Change-Id: Ide6a6188b9a19f4680cd79b55dcc842bbe98e174
Reviewed-by: Katja Marttila <katja.marttila@qt.io>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/libs/installer/packagemanagercore.cpp b/src/libs/installer/packagemanagercore.cpp
index da5412dd7..9feb195d8 100644
--- a/src/libs/installer/packagemanagercore.cpp
+++ b/src/libs/installer/packagemanagercore.cpp
@@ -639,6 +639,12 @@ void PackageManagerCore::componentsToInstallNeedsRecalculation()
  */
 bool PackageManagerCore::recalculateAllComponents()
 {
+    // Clear previous results first, as the check states are updated
+    // at the end of both calculate methods, which refer to the results
+    // from both calculators. Needed to keep the state correct.
+    d->clearInstallerCalculator();
+    d->clearUninstallerCalculator();
+
     if (!calculateComponentsToInstall())
         return false;
     if (!isInstaller() && !calculateComponentsToUninstall())