Don't hide command errors in tab modifier commands.

--HG--
extra : rebase_source : 05de0074fabbae061e14c10073f0b4648d72709f

common/content/tabs.js

@@ -624,7 +624,7 @@ var Tabs = Module("tabs", {
                 let alternate = tabs.alternate;
 
                 try {
-                    commands.execute(args[0] || "", null, true);
+                    dactyl.execute(args[0], null, true);
                 }
                 finally {
                     tabs.updateSelectionHistory([tabs.getTab(), alternate]);
@@ -641,7 +641,7 @@ var Tabs = Module("tabs", {
             function (args) {
                 dactyl.withSavedValues(["forceNewTab"], function () {
                     this.forceNewTab = true;
-                    commands.execute(args[0] || "", null, true);
+                    dactyl.execute(args[0], null, true);
                 });
             }, {
                 argCount: "+",

common/tests/functional/testCommands.js

@@ -328,9 +328,10 @@ var tests = {
         multiOutput: [""]
     },
     keepalt: {
-        error: [""],
+        error: ["", "some-nonexistent-command"],
         noOutput: ["js ''"],
-        anyOutput: ["echo 'foo'"]
+        anyOutput: ["echo 'foo'"],
+        completions: [["", hasItems]]
     },
     let: {}, // Deprecated. Fuck it.
     listcommands: {
@@ -671,10 +672,20 @@ var tests = {
             ["-index=", hasNItems(2)]
         ]
     },
-    tab: {},
+    tab: {
+        error: ["", "some-nonexistent-command"],
+        noOutput: ["js ''"],
+        anyOutput: ["echo 'foo'"],
+        completions: [["", hasItems]]
+    },
     tabattach: {},
     tabdetach: {},
-    tabdo: {},
+    tabdo: {
+        error: ["", "some-nonexistent-command"],
+        noOutput: ["js ''"],
+        anyOutput: ["echo 'foo'"],
+        completions: [["", hasItems]]
+    },
     tabduplicate: {},
     tablast: {},
     tabmove: {