[Tools] testbot: Validate and adjust the VM limits on startup.

Signed-off-by: Francois Gouget <[email protected]>
---
 testbot/bin/Engine.pl           | 15 +++++++++++++++
 testbot/lib/WineTestBot/Jobs.pm |  5 ++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/testbot/bin/Engine.pl b/testbot/bin/Engine.pl
index fe16f178..9b497023 100755
--- a/testbot/bin/Engine.pl
+++ b/testbot/bin/Engine.pl
@@ -700,6 +700,21 @@ sub main()
   $WineTestBot::Engine::Notify::RunningInEngine = 1;
   LogMsg "Starting the WineTestBot Engine\n";
 
+  # Validate and adjust the configuration options
+  $MaxActiveVMs ||= 1;
+  $MaxRevertingVMs ||= $MaxActiveVMs;
+  if ($MaxRevertingVMs > $MaxActiveVMs)
+  {
+    $MaxRevertingVMs = $MaxActiveVMs;
+    LogMsg "Capping MaxRevertingVMs to MaxActiveVMs ($MaxRevertingVMs)\n";
+  }
+  $MaxRevertsWhileRunningVMs ||= 0;
+  if ($MaxRevertsWhileRunningVMs > $MaxRevertingVMs)
+  {
+    $MaxRevertsWhileRunningVMs = $MaxRevertingVMs;
+    LogMsg "Capping MaxRevertsWhileRunningVMs to MaxRevertingVMs ($MaxRevertsWhileRunningVMs)\n";
+  }
+  $MaxVMsWhenIdle ||= $MaxActiveVMs;
   Cleanup();
 
   # Check for patches that arrived while the server was off.
diff --git a/testbot/lib/WineTestBot/Jobs.pm b/testbot/lib/WineTestBot/Jobs.pm
index 3a3e5177..3c7ce0df 100644
--- a/testbot/lib/WineTestBot/Jobs.pm
+++ b/testbot/lib/WineTestBot/Jobs.pm
@@ -691,15 +691,14 @@ sub ScheduleOnHost($$$)
   }
 
   # Finally, if we are otherwise idle, prepare some VMs for future jobs
-  my $MaxIdleVMs = defined $MaxVMsWhenIdle ? $MaxVMsWhenIdle : $MaxActiveVMs;
-  if ($ActiveCount - $IdleCount == 0 && $ActiveCount < $MaxIdleVMs)
+  if ($ActiveCount == $IdleCount && $ActiveCount < $MaxVMsWhenIdle)
   {
     # Sort from most important to least important
     my @SortedVMs = sort { $VMPriorities{$b} <=> $VMPriorities{$a} } keys %VMPriorities;
     foreach my $VMKey (@SortedVMs)
     {
       last if ($RevertingCount == $MaxReverts);
-      last if ($ActiveCount >= $MaxIdleVMs);
+      last if ($ActiveCount >= $MaxVMsWhenIdle);
 
       my $VM = $HostVMs->GetItem($VMKey);
       next if ($VM->Status ne "off");
-- 
2.14.2