Fix indexing error in conversation list search.

Only allow pinning of accepted contacts

lib/models/contact.dart

@@ -314,4 +314,8 @@ class ContactInfoState extends ChangeNotifier {
     notifyListeners();
   }
 
+  // returns true only if the conversation has been accepted, and has not been blocked
+  bool isAccepted() {
+    return _accepted && !_blocked;
+  }
 }

lib/views/contactsview.dart

@@ -227,11 +227,11 @@ class _ContactsViewState extends State<ContactsView> {
 
     var contactList = ScrollablePositionedList.separated(
       itemScrollController: Provider.of<ProfileInfoState>(context).contactListScrollController,
-      itemCount: Provider.of<ContactListState>(context).num,
+      itemCount: Provider.of<ContactListState>(context).numFiltered,
       initialScrollIndex: initialScroll,
       shrinkWrap: true,
       physics: BouncingScrollPhysics(),
-      semanticChildCount: Provider.of<ContactListState>(context).num,
+      semanticChildCount: Provider.of<ContactListState>(context).numFiltered,
       itemBuilder: (context, index) {
         return tiles.elementAt(index);
       },

lib/widgets/contactrow.dart

@@ -19,7 +19,6 @@ class ContactRow extends StatefulWidget {
 }
 
 class _ContactRowState extends State<ContactRow> {
-
   bool isHover = false;
 
   @override
@@ -127,12 +126,15 @@ class _ContactRowState extends State<ContactRow> {
                         ),
                       ],
                     ))),
-
-              Visibility(visible: Platform.isAndroid || (!Platform.isAndroid && isHover) || contact.pinned, child:
-                IconButton(
+            Visibility(
+                // only allow pinning for non-blocked and accepted conversations,
+                visible: contact.isAccepted() && (Platform.isAndroid || (!Platform.isAndroid && isHover) || contact.pinned),
+                child: IconButton(
                   tooltip: contact.pinned ? AppLocalizations.of(context)!.tooltipUnpinConversation : AppLocalizations.of(context)!.tooltipPinConversation,
-                  icon: Icon(contact.pinned ? Icons.push_pin : Icons.push_pin_outlined,
-                    color: Provider.of<Settings>(context).theme.mainTextColor,),
+                  icon: Icon(
+                    contact.pinned ? Icons.push_pin : Icons.push_pin_outlined,
+                    color: Provider.of<Settings>(context).theme.mainTextColor,
+                  ),
                   onPressed: () {
                     if (contact.pinned) {
                       contact.unpin(context);