Allow trailing semicolon when parsing OSC 9;4

src/cascadia/TerminalCore/ITerminalApi.hpp

@@ -67,7 +67,7 @@ namespace Microsoft::Terminal::Core
         virtual bool AddHyperlink(std::wstring_view uri, std::wstring_view params) noexcept = 0;
         virtual bool EndHyperlink() noexcept = 0;
 
-        virtual bool SetTaskbarProgress(const size_t state, const size_t progress) noexcept = 0;
+        virtual bool SetTaskbarProgress(const ::Microsoft::Console::VirtualTerminal::DispatchTypes::TaskbarState state, const size_t progress) noexcept = 0;
 
         virtual bool SetWorkingDirectory(std::wstring_view uri) noexcept = 0;
         virtual std::wstring_view GetWorkingDirectory() noexcept = 0;

src/cascadia/TerminalCore/Terminal.hpp

@@ -17,6 +17,8 @@
 #include "../../cascadia/terminalcore/ITerminalApi.hpp"
 #include "../../cascadia/terminalcore/ITerminalInput.hpp"
 
+static constexpr size_t TaskbarMinProgress{ 10 };
+
 // You have to forward decl the ICoreSettings here, instead of including the header.
 // If you include the header, there will be compilation errors with other
 //      headers that include Terminal.hpp
@@ -125,7 +127,7 @@ class Microsoft::Terminal::Core::Terminal final :
     bool AddHyperlink(std::wstring_view uri, std::wstring_view params) noexcept override;
     bool EndHyperlink() noexcept override;
 
-    bool SetTaskbarProgress(const size_t state, const size_t progress) noexcept override;
+    bool SetTaskbarProgress(const ::Microsoft::Console::VirtualTerminal::DispatchTypes::TaskbarState state, const size_t progress) noexcept override;
     bool SetWorkingDirectory(std::wstring_view uri) noexcept override;
     std::wstring_view GetWorkingDirectory() noexcept override;
 

src/cascadia/TerminalCore/TerminalApi.cpp

@@ -629,10 +629,43 @@ bool Terminal::EndHyperlink() noexcept
 // - progress: indicates the progress value
 // Return Value:
 // - true
-bool Terminal::SetTaskbarProgress(const size_t state, const size_t progress) noexcept
+bool Terminal::SetTaskbarProgress(const ::Microsoft::Console::VirtualTerminal::DispatchTypes::TaskbarState state, const size_t progress) noexcept
 {
-    _taskbarState = state;
-    _taskbarProgress = progress;
+    _taskbarState = static_cast<size_t>(state);
+
+    switch (state)
+    {
+    case DispatchTypes::TaskbarState::Clear:
+        // Always set progress to 0 in this case
+        _taskbarProgress = 0;
+        break;
+    case DispatchTypes::TaskbarState::Set:
+        // Always set progress to the value given in this case
+        _taskbarProgress = progress;
+        break;
+    case DispatchTypes::TaskbarState::Indeterminate:
+        // Leave the progress value unchanged in this case
+        break;
+    case DispatchTypes::TaskbarState::Error:
+    case DispatchTypes::TaskbarState::Paused:
+        // In these 2 cases, if the given progress value is 0, then
+        // leave the progress value unchanged, unless the current progress
+        // value is 0, in which case set it to a 'minimum' value (10 in our case);
+        // if the given progress value is greater than 0, then set the progress value
+        if (progress == 0)
+        {
+            if (_taskbarProgress == 0)
+            {
+                _taskbarProgress = TaskbarMinProgress;
+            }
+        }
+        else
+        {
+            _taskbarProgress = progress;
+        }
+        break;
+    }
+
     if (_pfnTaskbarProgressChanged)
     {
         _pfnTaskbarProgressChanged();

src/cascadia/TerminalCore/TerminalDispatch.cpp

@@ -510,15 +510,15 @@ bool TerminalDispatch::DoConEmuAction(const std::wstring_view string) noexcept
         {
             // A state parameter is defined, parse it out
             const auto stateSuccess = Utils::StringToUint(til::at(parts, 1), state);
-            if (!stateSuccess)
+            if (!stateSuccess && !til::at(parts, 1).empty())
             {
                 return false;
             }
             if (parts.size() >= 3)
             {
                 // A progress parameter is also defined, parse it out
                 const auto progressSuccess = Utils::StringToUint(til::at(parts, 2), progress);
-                if (!progressSuccess)
+                if (!progressSuccess && !til::at(parts, 2).empty())
                 {
                     return false;
                 }
@@ -535,7 +535,7 @@ bool TerminalDispatch::DoConEmuAction(const std::wstring_view string) noexcept
             // progress is greater than the maximum allowed value, clamp it to the max
             progress = TaskbarMaxProgress;
         }
-        return _terminalApi.SetTaskbarProgress(state, progress);
+        return _terminalApi.SetTaskbarProgress(static_cast<DispatchTypes::TaskbarState>(state), progress);
     }
     // 9 is SetWorkingDirectory, which informs the terminal about the current working directory.
     else if (subParam == 9)

src/cascadia/UnitTests_TerminalCore/TerminalApiTest.cpp

@@ -388,6 +388,30 @@ void TerminalCoreUnitTests::TerminalApiTest::SetTaskbarProgress()
     // Additional params should be ignored, state and progress still set normally
     VERIFY_ARE_EQUAL(term.GetTaskbarState(), gsl::narrow<size_t>(1));
     VERIFY_ARE_EQUAL(term.GetTaskbarProgress(), gsl::narrow<size_t>(80));
+
+    // Edge cases + trailing semicolon testing
+    stateMachine.ProcessString(L"\x1b]9;4;2;\x9c");
+    // String should be processed correctly despite the trailing semicolon,
+    // taskbar progress should remain unchanged from previous value
+    VERIFY_ARE_EQUAL(term.GetTaskbarState(), gsl::narrow<size_t>(2));
+    VERIFY_ARE_EQUAL(term.GetTaskbarProgress(), gsl::narrow<size_t>(80));
+
+    stateMachine.ProcessString(L"\x1b]9;4;3;75\x9c");
+    // Given progress value should be ignored because this is the indeterminate state,
+    // so the progress value should remain unchanged
+    VERIFY_ARE_EQUAL(term.GetTaskbarState(), gsl::narrow<size_t>(3));
+    VERIFY_ARE_EQUAL(term.GetTaskbarProgress(), gsl::narrow<size_t>(80));
+
+    stateMachine.ProcessString(L"\x1b]9;4;0;50\x9c");
+    // Taskbar progress should be 0 (the given value should be ignored)
+    VERIFY_ARE_EQUAL(term.GetTaskbarState(), gsl::narrow<size_t>(0));
+    VERIFY_ARE_EQUAL(term.GetTaskbarProgress(), gsl::narrow<size_t>(0));
+
+    stateMachine.ProcessString(L"\x1b]9;4;2;\x9c");
+    // String should be processed correctly despite the trailing semicolon,
+    // taskbar progress should be set to a 'minimum', non-zero value
+    VERIFY_ARE_EQUAL(term.GetTaskbarState(), gsl::narrow<size_t>(2));
+    VERIFY_IS_GREATER_THAN(term.GetTaskbarProgress(), gsl::narrow<size_t>(0));
 }
 
 void TerminalCoreUnitTests::TerminalApiTest::SetWorkingDirectory()

src/terminal/adapter/DispatchTypes.hpp

@@ -249,6 +249,15 @@ namespace Microsoft::Console::VirtualTerminal::DispatchTypes
         Scrollback = 3
     };
 
+    enum class TaskbarState : size_t
+    {
+        Clear = 0,
+        Set = 1,
+        Error = 2,
+        Indeterminate = 3,
+        Paused = 4
+    };
+
     enum GraphicsOptions : size_t
     {
         Off = 0,