Fix for bug #45951. r=waterson.

content/xul/templates/src/nsXULTemplateBuilder.cpp

@@ -4457,15 +4457,27 @@ nsXULTemplateBuilder::FireNewlyMatchedRules(const ClusterKeySet& aNewKeys)
             nsCOMPtr<nsIContent> tmpl;
             bestmatch->mRule->GetContent(getter_AddRefs(tmpl));
 
-            BuildContentFromTemplate(tmpl, content, content, PR_TRUE,
-                                     VALUE_TO_IRDFRESOURCE(key->mMemberValue),
-                                     PR_TRUE, bestmatch, nsnull, nsnull);
+            PRBool contentsGenerated = PR_TRUE;
+            nsCOMPtr<nsIXULContent> xulcontent = do_QueryInterface(content);
+            if (xulcontent)
+                xulcontent->GetLazyState(nsIXULContent::eContainerContentsBuilt, contentsGenerated);
+
+            if (contentsGenerated) {
+                BuildContentFromTemplate(tmpl, content, content, PR_TRUE,
+                                         VALUE_TO_IRDFRESOURCE(key->mMemberValue),
+                                         PR_TRUE, bestmatch, nsnull, nsnull);
+
+                // Remember the best match as the new "last" match
+                matches->SetLastMatch(bestmatch);
+            }
+            else {
+                // If we don't build the content, then pretend we
+                // never saw this match.
+                matches->Remove(bestmatch);
+            }
 
             // Update the 'empty' attribute
             SetContainerAttrs(content, bestmatch);
-
-            // Remember the best match as the new "last" match
-            matches->SetLastMatch(bestmatch);
         }
     }
 

rdf/base/src/nsContainerEnumerator.cpp

@@ -146,26 +146,38 @@ ContainerEnumeratorImpl::HasMoreElements(PRBool* aResult)
 
     // Otherwise, we need to grovel
 
-    // Figure out the upper bound so we'll know when we're done.
-    nsCOMPtr<nsIRDFNode> nextValNode;
-    rv = mDataSource->GetTarget(mContainer, kRDF_nextVal, PR_TRUE, getter_AddRefs(nextValNode));
+    // Figure out the upper bound so we'll know when we're done. Since it's
+    // possible that we're targeting a composite datasource, we'll need to
+    // "GetTargets()" and take the maximum value of "nextVal" to know the
+    // upper bound.
+    PRInt32 count = 0;
+
+    nsCOMPtr<nsISimpleEnumerator> targets;
+    rv = mDataSource->GetTargets(mContainer, kRDF_nextVal, PR_TRUE, getter_AddRefs(targets));
     if (NS_FAILED(rv)) return rv;
 
-    if (rv != NS_OK)
-        return NS_ERROR_UNEXPECTED;
+    while (1) {
+        PRBool hasmore;
+        targets->HasMoreElements(&hasmore);
+        if (! hasmore)
+            break;
 
-    nsCOMPtr<nsIRDFLiteral> nextVal = do_QueryInterface(nextValNode);
-    if (! nextVal)
-        return NS_ERROR_UNEXPECTED;
+        nsCOMPtr<nsISupports> isupports;
+        targets->GetNext(getter_AddRefs(isupports));
 
-    nsXPIDLString nextValStr;
-    rv = nextVal->GetValue(getter_Copies(nextValStr));
-    if (NS_FAILED(rv)) return rv;
+        nsCOMPtr<nsIRDFLiteral> nextValLiteral = do_QueryInterface(isupports);
+        if (! nextValLiteral)
+             continue;
 
-    PRInt32 err;
-    PRInt32 count = nsAutoString(nextValStr).ToInteger(&err);
-    if (NS_FAILED(err))
-        return NS_ERROR_UNEXPECTED;
+         nsXPIDLString nextValStr;
+         nextValLiteral->GetValue(getter_Copies(nextValStr));
+
+         PRInt32 err;
+         PRInt32 nextVal = nsAutoString(nextValStr).ToInteger(&err);
+
+         if (nextVal > count)
+             count = nextVal;
+    }
 
     // Now iterate through each index.
     while (mNextIndex < count) {

rdf/content/src/nsXULTemplateBuilder.cpp

@@ -4457,15 +4457,27 @@ nsXULTemplateBuilder::FireNewlyMatchedRules(const ClusterKeySet& aNewKeys)
             nsCOMPtr<nsIContent> tmpl;
             bestmatch->mRule->GetContent(getter_AddRefs(tmpl));
 
-            BuildContentFromTemplate(tmpl, content, content, PR_TRUE,
-                                     VALUE_TO_IRDFRESOURCE(key->mMemberValue),
-                                     PR_TRUE, bestmatch, nsnull, nsnull);
+            PRBool contentsGenerated = PR_TRUE;
+            nsCOMPtr<nsIXULContent> xulcontent = do_QueryInterface(content);
+            if (xulcontent)
+                xulcontent->GetLazyState(nsIXULContent::eContainerContentsBuilt, contentsGenerated);
+
+            if (contentsGenerated) {
+                BuildContentFromTemplate(tmpl, content, content, PR_TRUE,
+                                         VALUE_TO_IRDFRESOURCE(key->mMemberValue),
+                                         PR_TRUE, bestmatch, nsnull, nsnull);
+
+                // Remember the best match as the new "last" match
+                matches->SetLastMatch(bestmatch);
+            }
+            else {
+                // If we don't build the content, then pretend we
+                // never saw this match.
+                matches->Remove(bestmatch);
+            }
 
             // Update the 'empty' attribute
             SetContainerAttrs(content, bestmatch);
-
-            // Remember the best match as the new "last" match
-            matches->SetLastMatch(bestmatch);
         }
     }