deal better with stale contents.xml file in local directory

direct/src/p3d/AppRunner.py

@@ -802,7 +802,8 @@ class AppRunner(DirectObject):
         self.readConfigXml()
         
 
-    def addPackageInfo(self, name, platform, version, hostUrl, hostDir = None):
+    def addPackageInfo(self, name, platform, version, hostUrl, hostDir = None,
+                       recurse = False):
         """ Called by the browser for each one of the "required"
         packages that were preloaded before starting the application.
         If for some reason the package isn't already downloaded, this
@@ -830,6 +831,11 @@ class AppRunner(DirectObject):
             platform = None
         package = host.getPackage(name, version, platform = platform)
         if not package:
+            if not recurse:
+                # Maybe the contents.xml file isn't current.  Re-fetch it.
+                if host.redownloadContentsFile(self.http):
+                    return self.addPackageInfo(name, platform, version, hostUrl, hostDir = hostDir, recurse = True)
+            
             message = "Couldn't find %s %s on %s" % (name, version, hostUrl)
             raise OSError, message
 

direct/src/p3d/HostInfo.py

@@ -106,10 +106,13 @@ class HostInfo:
             # https-protected hostUrl, it will be the cleartext channel.
             self.downloadUrlPrefix = self.hostUrlPrefix
 
-    def downloadContentsFile(self, http, redownload = False):
+    def downloadContentsFile(self, http, redownload = False,
+                             hashVal = None):
         """ Downloads the contents.xml file for this particular host,
         synchronously, and then reads it.  Returns true on success,
-        false on failure. """
+        false on failure.  If hashVal is not None, it should be a
+        HashVal object, which will be filled with the hash from the
+        new contents.xml file."""
 
         if self.hasCurrentContentsFile():
             # We've already got one.
@@ -159,6 +162,8 @@ class HostInfo:
             f = open(tempFilename.toOsSpecific(), 'wb')
             f.write(rf.getData())
             f.close()
+            if hashVal:
+                hashVal.hashString(rf.getData())
 
             if not self.readContentsFile(tempFilename, freshDownload = True):
                 self.notify.warning("Failure reading %s" % (url))
@@ -192,14 +197,15 @@ class HostInfo:
 
         # Now download it again.
         self.hasContentsFile = False
-        if not self.downloadContentsFile(http, redownload = True):
+        hv2 = HashVal()
+        if not self.downloadContentsFile(http, redownload = True,
+                                         hashVal = hv2):
             return False
 
-        hv2 = HashVal()
-        filename = Filename(self.hostDir, 'contents.xml')
-        hv2.hashFile(filename)
-
-        if hv1 != hv2:
+        if hv2 == HashVal():
+            self.notify.info("%s didn't actually redownload." % (url))
+            return False
+        elif hv1 != hv2:
             self.notify.info("%s has changed." % (url))
             return True
         else: