Fix ExecCommandWith for cmd.exe in Windows (#1072)

Close #1018

Run the command as is in cmd.exe with no parsing and escaping.
Explicity set cmd.SysProcAttr so execCommand does not escape the command.
Technically, the command should be escaped with ^ for special characters,
including ". This allows cmd.exe commands to be chained together.

See https://github.com/neovim/neovim/pull/7343#issuecomment-333350201

This commit also updates quoteEntry to use strings.Replace instead of
strconv.Quote which escapes more than \ and ".

src/terminal.go

@@ -1103,9 +1103,18 @@ func keyMatch(key int, event tui.Event) bool {
 		event.Type == tui.Mouse && key == tui.DoubleClick && event.MouseEvent.Double
 }
 
+func quoteEntryCmd(entry string) string {
+	escaped := strings.Replace(entry, `\`, `\\`, -1)
+	escaped = `"` + strings.Replace(escaped, `"`, `\"`, -1) + `"`
+	r, _ := regexp.Compile(`[&|<>()@^%!"]`)
+	return r.ReplaceAllStringFunc(escaped, func(match string) string {
+		return "^" + match
+	})
+}
+
 func quoteEntry(entry string) string {
 	if util.IsWindows() {
-		return strconv.Quote(strings.Replace(entry, "\"", "\\\"", -1))
+		return quoteEntryCmd(entry)
 	}
 	return "'" + strings.Replace(entry, "'", "'\\''", -1) + "'"
 }

src/terminal_test.go

@@ -91,3 +91,22 @@ func TestReplacePlaceholder(t *testing.T) {
 	result = replacePlaceholder("echo {}/{1}/{3}/{2..3}", true, Delimiter{regex: regex}, false, "query", items1)
 	check("echo '  foo'\\''bar baz'/'f'/'r b'/''\\''bar b'")
 }
+
+func TestQuoteEntryCmd(t *testing.T) {
+	tests := map[string]string{
+		`"`:                       `^"\^"^"`,
+		`\`:                       `^"\\^"`,
+		`\"`:                      `^"\\\^"^"`,
+		`"\\\"`:                   `^"\^"\\\\\\\^"^"`,
+		`&|<>()@^%!`:              `^"^&^|^<^>^(^)^@^^^%^!^"`,
+		`%USERPROFILE%`:           `^"^%USERPROFILE^%^"`,
+		`C:\Program Files (x86)\`: `^"C:\\Program Files ^(x86^)\\^"`,
+	}
+
+	for input, expected := range tests {
+		escaped := quoteEntryCmd(input)
+		if escaped != expected {
+			t.Errorf("Input: %s, expected: %s, actual %s", input, expected, escaped)
+		}
+	}
+}

src/util/util_windows.go

@@ -6,8 +6,6 @@ import (
 	"os"
 	"os/exec"
 	"syscall"
-
-	"github.com/mattn/go-shellwords"
 )
 
 // ExecCommand executes the given command with cmd
@@ -18,11 +16,13 @@ func ExecCommand(command string) *exec.Cmd {
 // ExecCommandWith executes the given command with cmd. _shell parameter is
 // ignored on Windows.
 func ExecCommandWith(_shell string, command string) *exec.Cmd {
-	args, _ := shellwords.Parse(command)
-	allArgs := make([]string, len(args)+1)
-	allArgs[0] = "/c"
-	copy(allArgs[1:], args)
-	return exec.Command("cmd", allArgs...)
+	cmd := exec.Command("cmd")
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+	    HideWindow: false,
+	    CmdLine: fmt.Sprintf(` /s /c "%s"`, command),
+	    CreationFlags: 0,
+	}
+	return cmd
 }
 
 // IsWindows returns true on Windows