Encode our upgrade policy in productMatches/versionMatches and enforce it.

For Fedora, this means we will not allow upgrades of detected root filesystems
more than two releases old, or "upgrading" a newer install with an older one.
For RHEL, we don't yet know what to do so just allow things to continue as they
always have.  Using "upgradeany" still circumvents this check.

1 files changed, 32 insertions, 0 deletions

diff --git a/installclasses/fedora.py b/installclasses/fedora.py
index 3e529c501..0eda0b5c8 100644
--- a/installclasses/fedora.py
+++ b/installclasses/fedora.py
@@ -19,6 +19,7 @@
 
 from installclass import BaseInstallClass
 from constants import *
+from product import *
 from filer import *
 from flags import flags
 import os, types
@@ -76,5 +77,36 @@ class InstallClass(BaseInstallClass):
         else:
             return yuminstall.YumBackend
 
+    def productMatches(self, oldprod):
+        if oldprod.startswith(productName):
+            return True
+
+        productUpgrades = {
+                "Fedora Core": ("Red Hat Linux", ),
+                "Fedora": ("Fedora Core", )
+        }
+
+        if productUpgrades.has_key(productName):
+            acceptable = productUpgrades[productName]
+        else:
+            acceptable = ()
+
+        for p in acceptable:
+            if oldprod.startswith(p):
+                return True
+
+        return False
+
+    def versionMatches(self, oldver):
+        try:
+            oldVer = float(oldver)
+            newVer = float(productVersion)
+        except ValueError:
+            return True
+
+        # This line means we do not support upgrading from anything older
+        # than two versions ago!
+        return newVer > oldVer and newVer - oldVer <= 2
+
     def __init__(self):
 	BaseInstallClass.__init__(self)