Merge pull request #2336 from lzybkr/stdin_fixes

Fix some issues with `powershell -Command -`

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleControl.cs

@@ -3467,6 +3467,9 @@ namespace Microsoft.PowerShell
             [DllImport(PinvokeDllNames.GetLargestConsoleWindowSizeDllName, SetLastError = true, CharSet = CharSet.Unicode)]
             internal static extern COORD GetLargestConsoleWindowSize(NakedWin32Handle consoleOutput);
 
+            [DllImport(PinvokeDllNames.GetStdHandleDllName, SetLastError = true, CharSet = CharSet.Unicode)]
+            internal static extern IntPtr GetStdHandle(int handleId);
+
             [DllImport(PinvokeDllNames.ReadConsoleDllName, SetLastError = true, CharSet = CharSet.Unicode)]
             internal static extern bool ReadConsole
             (

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHost.cs

@@ -2868,6 +2868,25 @@ namespace Microsoft.PowerShell
         private System.Threading.Thread _breakHandlerThread;
         private bool _isDisposed;
         internal ConsoleHostUserInterface ui;
+
+#if CORECLR
+        internal Lazy<TextReader> ConsoleIn { get; } = new Lazy<TextReader>(() => Console.In);
+#else
+        internal Lazy<TextReader> ConsoleIn { get; } = new Lazy<TextReader>(() =>
+        {
+            // This is a workaround for a full clr issue that causes a hang when calling PowerShell from ruby.
+            // They use named pipes instead of anonymous pipes, and for some reason that triggers a hang
+            // reading from Console.In.
+            var inputHandle = ConsoleControl.NativeMethods.GetStdHandle(-10);
+            var s = new FileStream(new ConsoleHandle(inputHandle, false), FileAccess.Read);
+
+            uint codePage = (uint) ConsoleControl.NativeMethods.GetConsoleCP();
+            Encoding encoding = Encoding.GetEncoding((int) codePage);
+
+            return TextReader.Synchronized(new StreamReader(s, encoding, false));
+        });
+#endif
+
         private string _savedWindowTitle = "";
         private Version _ver = PSVersionInfo.PSVersion;
         private int _exitCodeFromRunspace;

src/Microsoft.PowerShell.ConsoleHost/host/msh/ConsoleHostUserInterface.cs

@@ -1554,19 +1554,22 @@ namespace Microsoft.PowerShell
         private string ReadLineFromFile(string initialContent)
         {
             var sb = new StringBuilder();
-            if (initialContent != null)
+            if (!string.IsNullOrEmpty(initialContent))
             {
                 sb.Append(initialContent);
                 sb.Append('\n');
             }
 
+            var consoleIn = _parent.ConsoleIn.Value;
             while (true)
             {
-                var inC = Console.In.Read();
+                var inC = consoleIn.Read();
                 if (inC == -1)
                 {
                     // EOF - we return null which tells our caller to exit
-                    return null;
+                    // but only if we don't have any input, we could have
+                    // input and then stdin was closed, but never saw a newline.
+                    return sb.Length == 0 ? null : sb.ToString();
                 }
 
                 var c = unchecked((char)inC);
@@ -1575,10 +1578,10 @@ namespace Microsoft.PowerShell
                 if (c == '\r')
                 {
                     // Treat as newline, but consume \n if there is one.
-                    if (Console.In.Peek() == '\n')
+                    if (consoleIn.Peek() == '\n')
                     {
                         if (!NoPrompt) Console.Out.Write('\n');
-                        Console.In.Read();
+                        consoleIn.Read();
                     }
                     break;
                 }
@@ -1588,7 +1591,9 @@ namespace Microsoft.PowerShell
                     break;
                 }
 
-                if (c == '\b')
+                // If NoPrompt is true, we are in a sort of server mode where we shouldn't
+                // do anything like edit the command line - every character is part of the input.
+                if (c == '\b' && !NoPrompt)
                 {
                     sb.Remove(sb.Length - 1, 1);
                 }

src/Microsoft.PowerShell.ConsoleHost/host/msh/Executor.cs

@@ -212,8 +212,7 @@ namespace Microsoft.PowerShell
                 if ((options & ExecutionOptions.ReadInputObjects) > 0 && Console.IsInputRedirected)
                 {
                     // read input objects from stdin
-
-                    WrappedDeserializer des = new WrappedDeserializer(_parent.InputFormat, "Input", Console.In);
+                    WrappedDeserializer des = new WrappedDeserializer(_parent.InputFormat, "Input", _parent.ConsoleIn.Value);
                     while (!des.AtEnd)
                     {
                         object o = des.Deserialize();

test/powershell/Host/ConsoleHost.Tests.ps1

@@ -227,6 +227,12 @@ Describe "ConsoleHost unit tests" -tags "Feature" {
             $process.StandardInput.Write("1+2`n")
             $process.StandardOutput.ReadLine() | Should Be "PS> 1+2"
             $process.StandardOutput.ReadLine() | Should Be "3"
+
+            # Backspace should work as expected
+            $process.StandardInput.Write("1+2`b3`n")
+            # A real console should render 2`b3 as just 3, but we're just capturing exactly what is written
+            $process.StandardOutput.ReadLine() | Should Be "PS> 1+2`b3"
+            $process.StandardOutput.ReadLine() | Should Be "4"
             $process.StandardInput.Close()
             $process.StandardOutput.ReadToEnd() | Should Be "PS> "
             EnsureChildHasExited $process
@@ -279,7 +285,16 @@ foo
 "@)
             $process.StandardOutput.ReadLine() | Should Be "in foo"
 
+            # Backspace sent through stdin should be in the final string
+            $process.StandardInput.Write("`"a`bc`".Length`n")
+            $process.StandardOutput.ReadLine() | Should Be "3"
+
+            # Last command with no newline - should be accepted and
+            # produce output after closing stdin.
+            $process.StandardInput.Write('22 + 22')
             $process.StandardInput.Close()
+            $process.StandardOutput.ReadLine() | Should Be "44"
+
             EnsureChildHasExited $process
         }