Fix vscode shell integration issues.

- Command history is captured correctly.
- Decorations show up on the correct lines.
- Transient prompt is suppressed because VSCode can't handle it
  (suppressing the transient prompt requires Clink v1.4.25 or higher).

vscode_shell_integration.lua

@@ -7,18 +7,57 @@ if not gizmo_vscode_shell_integration then
     return
 end
 
+-- VSCode shell integration escape codes are described in:
+-- https://code.visualstudio.com/docs/terminal/shell-integration
+
 local function is_vscode()
     local term_program = os.getenv("term_program") or ""
     if term_program:lower() == "vscode" then
         return true
     end
 end
 
-local function send_context()
+local function escape_command_line(line)
+    line = line:gsub("\\", "\\\\")
+    line = line:gsub(" ", "\\x20")
+    if line:find("[\x01-\x1f;]") then
+        line = line:gsub(";", "\\x3b")
+        for i = 0x01, 0x1f, 1 do
+            line = line:gsub(string.char(i), "\\x" .. i)
+        end
+    end
+    return line
+end
+
+local function begin_execution(line)
     if is_vscode() then
         local codes = ""
-        codes = codes .. "\027]633;D;" .. os.geterrorlevel() .. "\a" -- send command exit code
-        codes = codes .. "\027]633;P;Cwd=" .. os.getcwd() .. "\a" -- send cwd as title
+
+        -- Mark pre-execution.
+        codes = codes .. "\027]633;C\a"
+
+        -- Explicitly set the command line.
+        codes = codes .. "\027]633;E;" .. escape_command_line(line) .. "\a"
+
+        clink.print(codes, NONL)
+    end
+end
+
+local function finish_execution()
+    if is_vscode() then
+        local codes = ""
+
+        -- Mark execution finished with exit code.
+        codes = codes .. "\027]633;D"
+        if os.geterrorlevel and settings.get("cmd.get_errorlevel") then
+            codes = codes .. ";" .. os.geterrorlevel()
+        end
+        codes = codes .. "\a"
+
+        -- Set properties.
+        codes = codes .. "\027]633;P;Cwd=" .. os.getcwd() .. "\a"
+        codes = codes .. "\027]633;P;IsWindows=True\a"
+
         clink.print(codes, NONL)
     end
 end
@@ -29,21 +68,34 @@ function p:filter() -- luacheck: no unused
     -- Nothing to do here, but the filter function must be defined.
 end
 
+function p:transientfilter() -- luacheck: no unused
+    if (clink.version_encoded or 0) < 10040025 then
+        -- Disabling transient prompt requires v1.4.25 or higher.
+        return
+    end
+    if is_vscode() then
+        -- VSCode gets confused about prompt position and annotations when
+        -- transient prompt is used, so disable it in VSCode terminal windows.
+        return nil, false
+    end
+end
+
 function p:surround() -- luacheck: no unused
     if is_vscode() then
         local pre, suf
         local rpre, rsuf
 
-        -- ESC codes surrounding prompt string
-        pre = "\027]633;A\a" -- copied from shellIntegration-rc.zsh
-        suf = "\027]633;B\a" -- copied from shellIntegration-rc.zsh
+        -- Mark prompt start and end.
+        pre = "\027]633;A\a"
+        suf = "\027]633;B\a"
 
-        -- ESC codes surrounding right side prompt string
-        rpre = "\027]633;H\a" -- copied from shellIntegration-rc.zsh
-        rsuf = "\027]633;I\a" -- copied from shellIntegration-rc.zsh
+        -- Mark right side prompt start and end.
+        rpre = "\027]633;H\a"
+        rsuf = "\027]633;I\a"
 
         return pre, suf, rpre, rsuf
     end
 end
 
-clink.onbeginedit(send_context)
+clink.onbeginedit(finish_execution)
+clink.onendedit(begin_execution)