[partition] Introduce a check if the GPT-on-BIOS popup should be shown

The check is bogus right now, and it still always warns; but if
the `shouldWarnForGPTOnBIOS()` function is implemented, this will
fix issue 1701.

src/modules/partition/gui/PartitionViewStep.cpp

@@ -395,6 +395,18 @@ PartitionViewStep::onActivate()
     }
 }
 
+static bool
+shouldWarnForGPTOnBIOS( const PartitionCoreModule* core )
+{
+    if ( PartUtils::isEfiSystem() )
+    {
+        return false;
+    }
+
+    cDebug() << core->bootLoaderInstallPath();
+
+    return true;
+}
 
 void
 PartitionViewStep::onLeave()
@@ -462,9 +474,9 @@ PartitionViewStep::onLeave()
         {
 
             cDebug() << "device: BIOS";
-            // TODO: this *always* warns, which might be annoying, so it'd be
-            //       best to find a way to detect that bios_grub partition.
 
+            if ( shouldWarnForGPTOnBIOS( m_core ) )
+            {
                 QString message = tr( "Option to use GPT on BIOS" );
                 QString description = tr( "A GPT partition table is the best option for all "
                                           "systems. This installer supports such a setup for "
@@ -481,6 +493,7 @@ PartitionViewStep::onLeave()
 
                 QMessageBox::information( m_manualPartitionPage, message, description );
             }
+        }
 
         Partition* root_p = m_core->findPartitionByMountPoint( "/" );
         Partition* boot_p = m_core->findPartitionByMountPoint( "/boot" );