Add support for opening the Suggestions UI with recent commands

.github/actions/spelling/allow/allow.txt

@@ -95,6 +95,7 @@ slnt
 Sos
 ssh
 stakeholders
+sxn
 timeline
 timelines
 timestamped

.github/actions/spelling/expect/expect.txt

@@ -315,6 +315,7 @@ CPLINFO
 cplusplus
 CPPCORECHECK
 cppcorecheckrules
+cpprest
 cpprestsdk
 cppwinrt
 CProc
@@ -1452,6 +1453,7 @@ PPEB
 ppf
 ppguid
 ppidl
+pplx
 PPROC
 ppropvar
 ppsi

src/buffer/out/Row.cpp

@@ -949,11 +949,12 @@ std::wstring_view ROW::GetText() const noexcept
 
 std::wstring_view ROW::GetText(til::CoordType columnBegin, til::CoordType columnEnd) const noexcept
 {
-    const til::CoordType columns = _columnCount;
-    const auto colBeg = std::max(0, std::min(columns, columnBegin));
-    const auto colEnd = std::max(colBeg, std::min(columns, columnEnd));
-    const size_t chBeg = _uncheckedCharOffset(gsl::narrow_cast<size_t>(colBeg));
-    const size_t chEnd = _uncheckedCharOffset(gsl::narrow_cast<size_t>(colEnd));
+    // This ensures that `chEnd >= chBeg` will always be true.
+    // That way we can safely calculate `chEnd - chBeg`.
+    columnEnd = std::max(columnBegin, columnEnd);
+
+    const size_t chBeg = _uncheckedCharOffset(_clampedColumnInclusive(columnBegin));
+    const size_t chEnd = _uncheckedCharOffset(_clampedColumnInclusive(columnEnd));
 #pragma warning(suppress : 26481) // Don't use pointer arithmetic. Use span instead (bounds.1).
     return { _chars.data() + chBeg, chEnd - chBeg };
 }

src/cascadia/LocalTests_TerminalApp/pch.h

@@ -74,3 +74,5 @@ Author(s):
 #include "../../inc/DefaultSettings.h"
 
 #include <cppwinrt_utils.h>
+
+#include <til/winrt.h>

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -1257,6 +1257,34 @@ namespace winrt::TerminalApp::implementation
         }
     }
 
+    void TerminalPage::_HandleSuggestions(const IInspectable& /*sender*/,
+                                          const ActionEventArgs& args)
+    {
+        if (args)
+        {
+            if (const auto& realArgs = args.ActionArgs().try_as<SuggestionsArgs>())
+            {
+                auto source = realArgs.Source();
+
+                switch (source)
+                {
+                case SuggestionsSource::CommandHistory:
+                {
+                    if (const auto& control{ _GetActiveControl() })
+                    {
+                        const auto context = control.CommandHistory();
+                        _OpenSuggestions(control,
+                                         Command::HistoryToCommands(context.History(), context.CurrentCommandline(), false),
+                                         SuggestionsMode::Palette);
+                    }
+                    args.Handled(true);
+                }
+                break;
+                }
+            }
+        }
+    }
+
     void TerminalPage::_HandleColorSelection(const IInspectable& /*sender*/,
                                              const ActionEventArgs& args)
     {