From fee3fdf3221f512fea081a15c494e1a83ac9d4f3 Mon Sep 17 00:00:00 2001
From: d-bingham <bingham@cs.wisc.edu>
Date: Wed, 6 Nov 2019 08:02:55 -0600
Subject: [PATCH] Replacing \r\n line endings with \r line endings (#3449)

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## Summary of the Pull Request

<!-- Other than the issue solved, is this relevant to any other issues/existing PRs? -->
## References

#1091
#1094
#2390
#3314

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## PR Checklist
* [x] Closes #1091
* [x] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA
* [ ] Tests added/passed
* [ ] Requires documentation to be updated
* [x] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

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## Detailed Description of the Pull Request / Additional comments

Combination of the PRs #1094, #2390, and #3314, especially as discussed in #3314.

In short, this changes line endings from Windows-space \r\n to the more universal \r.

<!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

Copied and pasted text into the terminal without the patch, line endings were doubled.
With the patch, line endings weren't doubled.


--------------------

* Replacing \r\n line endings with \r line endings

* Fixing Formatting
---
 src/cascadia/TerminalControl/TermControl.cpp | 31 +++++++++++++++++++-
 src/cascadia/TerminalControl/TermControl.h   |  1 +
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/cascadia/TerminalControl/TermControl.cpp b/src/cascadia/TerminalControl/TermControl.cpp
index aa764e02ca..a75cbee7c0 100644
--- a/src/cascadia/TerminalControl/TermControl.cpp
+++ b/src/cascadia/TerminalControl/TermControl.cpp
@@ -1205,6 +1205,35 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
         _connection.WriteInput(wstr);
     }
 
+    // Method Description:
+    // - Pre-process text pasted (presumably from the clipboard)
+    //   before sending it over the terminal's connection, converting
+    //   Windows-space \r\n line-endings to \r line-endings
+    void TermControl::_SendPastedTextToConnection(const std::wstring& wstr)
+    {
+        // Some notes on this implementation:
+        //
+        // - std::regex can do this in a single line, but is somewhat
+        //   overkill for a simple search/replace operation (and its
+        //   performance guarantees aren't exactly stellar)
+        // - The STL doesn't have a simple string search/replace method.
+        //   This fact is lamentable.
+        // - This line-ending converstion is intentionally fairly
+        //   conservative, to avoid stripping out lone \n characters
+        //   where they could conceivably be intentional.
+
+        std::wstring stripped{ wstr };
+
+        std::wstring::size_type pos = 0;
+
+        while ((pos = stripped.find(L"\r\n", pos)) != std::wstring::npos)
+        {
+            stripped.replace(pos, 2, L"\r");
+        }
+
+        _connection.WriteInput(stripped);
+    }
+
     // Method Description:
     // - Update the font with the renderer. This will be called either when the
     //      font changes or the DPI changes, as DPI changes will necessitate a
@@ -1456,7 +1485,7 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
     {
         // attach TermControl::_SendInputToConnection() as the clipboardDataHandler.
         // This is called when the clipboard data is loaded.
-        auto clipboardDataHandler = std::bind(&TermControl::_SendInputToConnection, this, std::placeholders::_1);
+        auto clipboardDataHandler = std::bind(&TermControl::_SendPastedTextToConnection, this, std::placeholders::_1);
         auto pasteArgs = winrt::make_self<PasteFromClipboardEventArgs>(clipboardDataHandler);
 
         // send paste event up to TermApp
diff --git a/src/cascadia/TerminalControl/TermControl.h b/src/cascadia/TerminalControl/TermControl.h
index ee3597ba46..146ae5f222 100644
--- a/src/cascadia/TerminalControl/TermControl.h
+++ b/src/cascadia/TerminalControl/TermControl.h
@@ -165,6 +165,7 @@ namespace winrt::Microsoft::Terminal::TerminalControl::implementation
         void _BlinkCursor(Windows::Foundation::IInspectable const& sender, Windows::Foundation::IInspectable const& e);
         void _SetEndSelectionPointAtCursor(Windows::Foundation::Point const& cursorPosition);
         void _SendInputToConnection(const std::wstring& wstr);
+        void _SendPastedTextToConnection(const std::wstring& wstr);
         void _SwapChainSizeChanged(Windows::Foundation::IInspectable const& sender, Windows::UI::Xaml::SizeChangedEventArgs const& e);
         void _SwapChainScaleChanged(Windows::UI::Xaml::Controls::SwapChainPanel const& sender, Windows::Foundation::IInspectable const& args);
         void _DoResize(const double newWidth, const double newHeight);