Escape single quotes while translating dropped Win32 paths

When file/folder is dropped to the terminal, its path is translated and
quoted with a pair of single quotes if necessary.

However, despite that the Win32 subsystem allows single quote, the
terminal control does not escape it.  It causes a path containing one or
more single quotes incorrect on the POSIX shell context
(see Issue microsoft#18006 for an example).

With this commit, the terminal control escapes a single quote with a
valid escape sequence `'\''` (finish quote, print a single quote then
begin quote again) when the path translation is required.

Author: a4lg

src/cascadia/TerminalControl/TermControl.cpp

@@ -66,6 +66,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             /* Cygwin */ L"/cygdrive/",
             /* MSYS2 */ L"/",
         };
+        static constexpr wil::zwstring_view sSingleQuoteEscape = L"'\\''";
+        static constexpr auto cchSingleQuoteEscape = sSingleQuoteEscape.size();
 
         if (translationStyle == PathTranslationStyle::None)
         {
@@ -75,6 +77,16 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         // All of the other path translation modes current result in /-delimited paths
         std::replace(fullPath.begin(), fullPath.end(), L'\\', L'/');
 
+        // Escape single quotes, assuming translated paths are always quoted by single quotes.
+        size_t pos = 0;
+        while ((pos = fullPath.find(L'\'', pos)) != std::wstring::npos)
+        {
+            // ' -> '\''
+            fullPath.replace(pos, 1, sSingleQuoteEscape);
+            // Arithmetic overflow is not a problem since an exception would have thrown above on such cases.
+            pos += cchSingleQuoteEscape;
+        }
+
         if (fullPath.size() >= 2 && fullPath.at(1) == L':')
         {
             // C:/foo/bar -> Cc/foo/bar