fix: add shellexecute-on-windows feature.

That way, it's possible to toggle on a feature that might
cause issues in some dependency trees that contain `flate2`
with `zlib-ng` backend.

.github/workflows/cross-platform-testing.yml

@@ -72,6 +72,9 @@ jobs:
           echo "target flag is: ${{ env.TARGET_FLAGS }}"
           echo "target dir is: ${{ env.TARGET_DIR }}"
 
+      - name: Build with all features
+        if: startsWith(matrix.os, 'windows')
+        run: ${{ env.CARGO }} build ${{ env.TARGET_FLAGS }} --all-features
       - name: Build (and link)
         run: ${{ env.CARGO }} build ${{ env.TARGET_FLAGS }}
       - name: Run tests

Cargo.toml

@@ -12,6 +12,16 @@ keywords = ["open", "xdg-open", "start", "launch"]
 include = ["src/**/*", "LICENSE.md", "README.md", "changelog.md"]
 rust-version = "1.62"
 
+[features]
+## If enabled, link to `shell32` on Windows and use `ShellExecuteW` intead of a command invocation.
+## That way, it should be possible to open currently opened (for writing) files as well.
+##
+## However, if the `flate2` crate with zlib-ng backend is also used in the same tree, it maybe that
+## linkage fails.
+##
+## This feature is only effective on Windows.
+shellexecute-on-windows = []
+
 [[bin]]
 test = false
 doc = false

src/lib.rs

@@ -237,7 +237,7 @@ pub fn with_in_background<T: AsRef<OsStr>>(
 ///
 /// See documentation of [`that()`] for more details.
 pub fn that_detached(path: impl AsRef<OsStr>) -> io::Result<()> {
-    #[cfg(not(windows))]
+    #[cfg(any(not(feature = "shellexecute-on-windows"), not(windows)))]
     {
         let mut last_err = None;
         for mut cmd in commands(path) {
@@ -251,7 +251,7 @@ pub fn that_detached(path: impl AsRef<OsStr>) -> io::Result<()> {
         Err(last_err.expect("no launcher worked, at least one error"))
     }
 
-    #[cfg(windows)]
+    #[cfg(all(windows, feature = "shellexecute-on-windows"))]
     {
         windows::that_detached(path)
     }
@@ -263,13 +263,13 @@ pub fn that_detached(path: impl AsRef<OsStr>) -> io::Result<()> {
 ///
 /// See documentation of [`with()`] for more details.
 pub fn with_detached<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> io::Result<()> {
-    #[cfg(not(windows))]
+    #[cfg(any(not(feature = "shellexecute-on-windows"), not(windows)))]
     {
         let mut cmd = with_command(path, app);
         cmd.spawn_detached()
     }
 
-    #[cfg(windows)]
+    #[cfg(all(windows, feature = "shellexecute-on-windows"))]
     {
         windows::with_detached(path, app)
     }

src/windows.rs

@@ -39,6 +39,7 @@ fn wrap_in_quotes<T: AsRef<OsStr>>(path: T) -> OsString {
     result
 }
 
+#[cfg(feature = "shellexecute-on-windows")]
 pub fn that_detached<T: AsRef<OsStr>>(path: T) -> std::io::Result<()> {
     let path = wide(path);
 
@@ -54,6 +55,7 @@ pub fn that_detached<T: AsRef<OsStr>>(path: T) -> std::io::Result<()> {
     }
 }
 
+#[cfg(feature = "shellexecute-on-windows")]
 pub fn with_detached<T: AsRef<OsStr>>(path: T, app: impl Into<String>) -> std::io::Result<()> {
     let app = wide(app.into());
     let path = wide(path);
@@ -79,6 +81,7 @@ fn wide<T: AsRef<OsStr>>(input: T) -> Vec<u16> {
 ///
 /// <https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew>
 #[allow(non_snake_case)]
+#[cfg(feature = "shellexecute-on-windows")]
 pub unsafe fn ShellExecuteW(
     hwnd: isize,
     lpoperation: *const u16,
@@ -105,6 +108,7 @@ pub unsafe fn ShellExecuteW(
     }
 }
 
+#[cfg(feature = "shellexecute-on-windows")]
 mod ffi {
     /// Activates the window and displays it in its current size and position.
     ///