[vbox-dev] [PATCH] Fix for Guest "OS type" future-compatibility

[Alexey Eromenko]

Hi,

Today if I revert to older VirtualBox (to 4.3.20) from newer (v5.0
BETA), I lose access to certain VMs, such as "Windows 10", because it
has a new guest OS type ID.

Those VMs become "inaccessible" for no good reason. I can understand a
VM becoming "inaccessible" if hard disk new format is coming or a disk
image is lacking, but Guest OS type ?

My patch allows to recognize and start VMs with future guest OS type
IDs. They will revert to "unknown" OS type.

This is particularly useful in combination with "vbox-unattended"
patch, that adds new OS types every now and then, but also for Oracle
VirtualBox itself.

I have tested it together with VirtualBox GUI and with VBoxManage commands.
Plus tested OVF, Import / Export appliance.
-- 
-Alexey Eromenko "Technologov"
-------------- next part --------------
diff -uNr -U 6 vbox-orig/VirtualBox-5.0.0_BETA3//src/VBox/Main/src-server/VirtualBoxImpl.cpp vbox-guest-os-type/VirtualBox-5.0.0_BETA3//src/VBox/Main/src-server/VirtualBoxImpl.cpp
--- vbox-orig/VirtualBox-5.0.0_BETA3//src/VBox/Main/src-server/VirtualBoxImpl.cpp	2015-05-07 21:37:02.000000000 +0300
+++ vbox-guest-os-type/VirtualBox-5.0.0_BETA3//src/VBox/Main/src-server/VirtualBoxImpl.cpp	2015-05-08 01:04:43.000000000 +0300
@@ -1888,30 +1888,31 @@
 HRESULT VirtualBox::getGuestOSType(const com::Utf8Str &aId,
                                    ComPtr<IGuestOSType> &aType)
 {
     aType = NULL;
     AutoReadLock alock(m->allGuestOSTypes.getLockHandle() COMMA_LOCKVAL_SRC_POS);
 
-    HRESULT rc = S_OK;
     for (GuestOSTypesOList::iterator it = m->allGuestOSTypes.begin();
          it != m->allGuestOSTypes.end();
          ++it)
     {
         const Bstr &typeId = (*it)->i_id();
         AssertMsg(!typeId.isEmpty(), ("ID must not be NULL"));
         if (typeId.compare(aId, Bstr::CaseInsensitive) == 0)
         {
             (*it).queryInterfaceTo(aType.asOutParam());
             break;
         }
     }
-    return (aType) ? S_OK :
-        setError(E_INVALIDARG,
-                 tr("'%s' is not a valid Guest OS type"),
-                 aId.c_str());
-    return rc;
+    
+    // if Guest OS type is from future or devel version, we revert to "Other" or NULL.
+    if (!aType) 
+    {
+        aType = m->allGuestOSTypes.front();
+    }    
+    return S_OK;
 }
 
 HRESULT VirtualBox::createSharedFolder(const com::Utf8Str &aName,
                                        const com::Utf8Str &aHostPath,
                                        BOOL aWritable,
                                        BOOL aAutomount)