diff -up firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.cpp.gnome-shell-search-fixes firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.cpp
--- firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.cpp.gnome-shell-search-fixes	2020-04-07 08:01:50.587124776 +0200
+++ firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.cpp	2020-04-07 10:14:02.530380225 +0200
@@ -26,6 +26,8 @@
 #include "nsIStringBundle.h"
 #include "imgIContainer.h"
 #include "imgITools.h"
+#include "nsNetCID.h"
+#include "nsIIOService.h"
 
 #include "mozilla/gfx/DataSurfaceHelpers.h"
 
@@ -289,20 +291,12 @@ AsyncFaviconDataReady::OnComplete(nsIURI
 }
 
 void nsGNOMEShellSearchProvider::ComposeSearchResultReply(
-    DBusMessage* reply, const char* aSearchTerm) {
+    DBusMessage* reply, const char* aSearchTerm, bool aSearchOnly) {
   uint32_t childCount = 0;
-  nsresult rv = mHistResultContainer->GetChildCount(&childCount);
-  if (NS_FAILED(rv) || childCount == 0) {
-    return;
-  }
-
-  // Obtain the favicon service and get the favicon for the specified page
-  nsCOMPtr<nsIFaviconService> favIconSvc(
-      do_GetService("@mozilla.org/browser/favicon-service;1"));
-  nsCOMPtr<nsIIOService> ios(do_GetService(NS_IOSERVICE_CONTRACTID));
+  nsresult rv = NS_OK;
 
-  if (childCount > MAX_SEARCH_RESULTS_NUM) {
-    childCount = MAX_SEARCH_RESULTS_NUM;
+  if (!aSearchOnly) {
+    nsresult rv = mHistResultContainer->GetChildCount(&childCount);
   }
 
   DBusMessageIter iter;
@@ -310,30 +304,41 @@ void nsGNOMEShellSearchProvider::Compose
   DBusMessageIter iterArray;
   dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "s", &iterArray);
 
-  for (uint32_t i = 0; i < childCount; i++) {
-    nsCOMPtr<nsINavHistoryResultNode> child;
-    mHistResultContainer->GetChild(i, getter_AddRefs(child));
-    if (NS_WARN_IF(NS_FAILED(rv))) {
-      continue;
-    }
-    if (!IsHistoryResultNodeURI(child)) {
-      continue;
+  if (NS_SUCCEEDED(rv) && childCount > 0) {
+    // Obtain the favicon service and get the favicon for the specified page
+    nsCOMPtr<nsIFaviconService> favIconSvc(
+        do_GetService("@mozilla.org/browser/favicon-service;1"));
+    nsCOMPtr<nsIIOService> ios(do_GetService(NS_IOSERVICE_CONTRACTID));
+
+    if (childCount > MAX_SEARCH_RESULTS_NUM) {
+      childCount = MAX_SEARCH_RESULTS_NUM;
     }
 
-    nsAutoCString uri;
-    child->GetUri(uri);
+    for (uint32_t i = 0; i < childCount; i++) {
+      nsCOMPtr<nsINavHistoryResultNode> child;
+      mHistResultContainer->GetChild(i, getter_AddRefs(child));
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        continue;
+      }
+      if (!child || !IsHistoryResultNodeURI(child)) {
+        continue;
+      }
 
-    nsCOMPtr<nsIURI> iconIri;
-    ios->NewURI(uri, nullptr, nullptr, getter_AddRefs(iconIri));
-    nsCOMPtr<nsIFaviconDataCallback> callback =
-        new AsyncFaviconDataReady(this, i, mSearchSerial);
-    favIconSvc->GetFaviconDataForPage(iconIri, callback, 0);
+      nsAutoCString uri;
+      child->GetUri(uri);
 
-    nsAutoCString idKey;
-    GetIDKeyForURI(i, uri, idKey);
+      nsCOMPtr<nsIURI> iconIri;
+      ios->NewURI(uri, nullptr, nullptr, getter_AddRefs(iconIri));
+      nsCOMPtr<nsIFaviconDataCallback> callback =
+          new AsyncFaviconDataReady(this, i, mSearchSerial);
+      favIconSvc->GetFaviconDataForPage(iconIri, callback, 0);
 
-    const char* id = idKey.get();
-    dbus_message_iter_append_basic(&iterArray, DBUS_TYPE_STRING, &id);
+      nsAutoCString idKey;
+      GetIDKeyForURI(i, uri, idKey);
+
+      const char* id = idKey.get();
+      dbus_message_iter_append_basic(&iterArray, DBUS_TYPE_STRING, &id);
+    }
   }
 
   nsPrintfCString searchString("%s:%s", KEYWORD_SEARCH_STRING, aSearchTerm);
@@ -346,7 +351,7 @@ void nsGNOMEShellSearchProvider::Compose
 DBusHandlerResult nsGNOMEShellSearchProvider::GetInitialResultSet(
     DBusMessage* aMsg) {
   DBusMessage* reply;
-  char** stringArray;
+  char** stringArray = nullptr;
   int elements;
 
   if (!dbus_message_get_args(aMsg, nullptr, DBUS_TYPE_ARRAY, DBUS_TYPE_STRING,
@@ -356,9 +361,10 @@ DBusHandlerResult nsGNOMEShellSearchProv
   } else {
     reply = dbus_message_new_method_return(aMsg);
     nsresult rv = NewHistorySearch(stringArray[0]);
-    if (NS_SUCCEEDED(rv)) {
-      ComposeSearchResultReply(reply, stringArray[0]);
-    }
+    ComposeSearchResultReply(reply, stringArray[0],
+                             /* search only */ NS_FAILED(rv));
+  }
+  if (stringArray) {
     dbus_free_string_array(stringArray);
   }
 
@@ -384,9 +390,8 @@ DBusHandlerResult nsGNOMEShellSearchProv
   } else {
     reply = dbus_message_new_method_return(aMsg);
     nsresult rv = NewHistorySearch(stringArray[0]);
-    if (NS_SUCCEEDED(rv)) {
-      ComposeSearchResultReply(reply, stringArray[0]);
-    }
+    ComposeSearchResultReply(reply, stringArray[0],
+                             /* search only */ NS_FAILED(rv));
   }
 
   if (unusedArray) {
@@ -556,6 +561,10 @@ void nsGNOMEShellSearchProvider::LaunchW
     nsCOMPtr<nsINavHistoryResultNode> child;
     mHistResultContainer->GetChild(keyIndex, getter_AddRefs(child));
 
+    if (!child) {
+      return;
+    }
+
     nsAutoCString uri;
     nsresult rv = child->GetUri(uri);
     if (NS_FAILED(rv)) {
diff -up firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.h.gnome-shell-search-fixes firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.h
--- firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.h.gnome-shell-search-fixes	2020-04-07 08:01:50.587124776 +0200
+++ firefox-75.0/browser/components/shell/nsGNOMEShellSearchProvider.h	2020-04-07 09:56:30.857553820 +0200
@@ -70,7 +70,8 @@ class nsGNOMEShellSearchProvider : publi
   bool IsHistoryResultNodeURI(nsINavHistoryResultNode* aHistoryNode);
   void AppendResultID(DBusMessageIter* aIter, const char* aID);
   void AppendSearchID(DBusMessageIter* aIter, const char* aID);
-  void ComposeSearchResultReply(DBusMessage* aReply, const char* aSearchTerm);
+  void ComposeSearchResultReply(DBusMessage* aReply, const char* aSearchTerm,
+                                bool aSearchOnly);
   void LaunchWithID(const char* aID, uint32_t aTimeStamp);
   void LaunchWithAllResults(uint32_t aTimeStamp);