Fix exception after AcceptAndGetNext

The "current" line cleared after accepting via AcceptAndGetNext
and we would crash trying to recall this current line.

I've changed how history search works after AcceptAndGetNext
to work in a more natural way so that arrow keys can be used
to recall commands near the accepted command instead of
searching for other commands with the same prefix.

Fixes #152.

PSReadLine/Changes.txt

@@ -10,6 +10,7 @@ New features:
       Set-PSReadlineKeyHandler -Key Enter -Function AcceptLine
 
 Bug fixes:
+* Occasional exception with AcceptAndGetNext (Ctrl+O) followed by something other than Enter
 
 New functions:
 * ValidateAndAcceptLine

PSReadLine/History.cs

@@ -62,9 +62,16 @@ namespace PSConsoleUtilities
             {
                 ClearDemoWindow();
             }
-            _savedCurrentLine._line = null;
-            _savedCurrentLine._edits = null;
-            _savedCurrentLine._undoEditIndex = 0;
+
+            // Clear the saved line unless we used AcceptAndGetNext in which
+            // case we're really still in middle of history and might want
+            // to recall the saved line.
+            if (_getNextHistoryIndex == 0)
+            {
+                _savedCurrentLine._line = null;
+                _savedCurrentLine._edits = null;
+                _savedCurrentLine._undoEditIndex = 0;
+            }
             return result;
         }
 
@@ -284,7 +291,7 @@ namespace PSConsoleUtilities
             // to check if we need to load history from another sessions now.
             MaybeReadHistoryFile();
 
-            if (_singleton._currentHistoryIndex == _history.Count)
+            if (_savedCurrentLine._line == null)
             {
                 _savedCurrentLine._line = _buffer.ToString();
                 _savedCurrentLine._edits = _edits;

PSReadLine/ReadLine.cs

@@ -528,7 +528,6 @@ namespace PSConsoleUtilities
             _yankCommandCount = 0;
             _yankLastArgCommandCount = 0;
             _tabCommandCount = 0;
-            _searchHistoryCommandCount = 0;
             _recallHistoryCommandCount = 0;
             _visualSelectionCommandCount = 0;
             _hashedHistory = null;
@@ -538,6 +537,18 @@ namespace PSConsoleUtilities
                 _currentHistoryIndex = _getNextHistoryIndex;
                 UpdateFromHistory(moveCursor: true);
                 _getNextHistoryIndex = 0;
+                if (_searchHistoryCommandCount > 0)
+                {
+                    _searchHistoryPrefix = "";
+                    if (Options.HistoryNoDuplicates)
+                    {
+                        _hashedHistory = new Dictionary<string, int>();
+                    }
+                }
+            }
+            else
+            {
+                _searchHistoryCommandCount = 0;
             }
         }
 

TestPSReadLine/Program.cs

@@ -106,13 +106,13 @@ namespace TestPSReadLine
 
             PSConsoleReadLine.SetOptions(new SetPSReadlineOption
             {
-                EditMode = EditMode.Windows,
+                EditMode = EditMode.Emacs,
                 HistoryNoDuplicates = true,
             });
             PSConsoleReadLine.SetKeyHandler(new[] {"Ctrl+LeftArrow"}, PSConsoleReadLine.ShellBackwardWord, "", "");
             PSConsoleReadLine.SetKeyHandler(new[] {"Ctrl+RightArrow"}, PSConsoleReadLine.ShellNextWord, "", "");
-            PSConsoleReadLine.SetKeyHandler(new[] {"UpArrow"}, PSConsoleReadLine.HistorySearchBackward, "", "");
-            PSConsoleReadLine.SetKeyHandler(new[] {"DownArrow"}, PSConsoleReadLine.HistorySearchForward, "", "");
+            PSConsoleReadLine.SetKeyHandler(new[] {"F4"}, PSConsoleReadLine.HistorySearchBackward, "", "");
+            PSConsoleReadLine.SetKeyHandler(new[] {"F5"}, PSConsoleReadLine.HistorySearchForward, "", "");
             //PSConsoleReadLine.SetKeyHandler(new[] {"Ctrl+D,Ctrl+E"}, PSConsoleReadLine.EnableDemoMode, "", "");
             //PSConsoleReadLine.SetKeyHandler(new[] {"Ctrl+D,Ctrl+D"}, PSConsoleReadLine.DisableDemoMode, "", "");
             PSConsoleReadLine.SetKeyHandler(new[] {"Ctrl+D,Ctrl+C"}, PSConsoleReadLine.CaptureScreen, "", "");
@@ -121,6 +121,7 @@ namespace TestPSReadLine
             PSConsoleReadLine.SetKeyHandler(new[] {"F6"}, PSConsoleReadLine.PreviousLine, "", "");
             PSConsoleReadLine.SetKeyHandler(new[] {"F7"}, PSConsoleReadLine.NextLine, "", "");
             PSConsoleReadLine.SetKeyHandler(new[] {"F2"}, PSConsoleReadLine.ValidateAndAcceptLine, "", "");
+            PSConsoleReadLine.SetKeyHandler(new[] {"Enter"}, PSConsoleReadLine.AcceptLine, "", "");
 
 
             EngineIntrinsics executionContext;

UnitTestPSReadLine/BasicEditingTest.cs

@@ -166,6 +166,29 @@ namespace UnitTestPSReadLine
             SetHistory("echo 1", "echo 2");
             Test("echo 1", Keys(_.UpArrow, _.UpArrow, _.CtrlO, InputAcceptedNow));
             Test("echo 2", Keys(_.Enter));
+
+            // Test that the current saved line is saved after AcceptAndGetNext
+            SetHistory("echo 1", "echo 2");
+            Test("echo 1", Keys("e", _.UpArrow, _.UpArrow, _.CtrlO, InputAcceptedNow));
+            Test("e", Keys(_.DownArrow, _.DownArrow, _.Enter));
+
+            // Test that we can edit after recalling the current line
+            SetHistory("echo 1", "echo 2");
+            Test("echo 1", Keys("e", _.UpArrow, _.UpArrow, _.CtrlO, InputAcceptedNow));
+            Test("eee", Keys(_.DownArrow, _.DownArrow, "ee", _.Enter));
+        }
+
+        [TestMethod]
+        public void TestAcceptAndGetNextWithHistorySearch()
+        {
+            TestSetup(KeyMode.Emacs,
+                      new KeyHandler("UpArrow", PSConsoleReadLine.HistorySearchBackward),
+                      new KeyHandler("DownArrow", PSConsoleReadLine.HistorySearchForward));
+
+            // Test that after AcceptAndGetNext, the previous search is not applied
+            SetHistory("echo 1", "echo 2", "zzz");
+            Test("echo 1", Keys("e", _.UpArrow, _.UpArrow, _.CtrlO, InputAcceptedNow));
+            Test("zzz", Keys(_.DownArrow, _.Enter));
         }
 
         [TestMethod]