Use msiexec /x for self uninstall

Author: Boddlnagg

Cargo.toml

@@ -28,6 +28,9 @@ rustls-backend = ["download/rustls-backend"]
 # Include in the default set to disable self-update and uninstall.
 no-self-update = []
 
+# Used to change behavior of self-update and uninstall if installed via MSI 
+msi-installed = []
+
 [dependencies]
 rustup-dist = { path = "src/rustup-dist", version = "0.5.0" }
 rustup-utils = { path = "src/rustup-utils", version = "0.5.0" }

src/rustup-cli/self_update.rs

@@ -571,6 +571,19 @@ pub fn uninstall(no_prompt: bool) -> Result<()> {
         err!("you should probably use your system package manager to uninstall rustup");
         process::exit(1);
     }
+
+    if cfg!(feature = "msi-installed") {
+        // Get the product code of the MSI installer from the registry
+        // and spawn `msiexec /x`, then exit immediately
+        let product_code = try!(get_msi_product_code());
+        try!(Command::new("msiexec")
+                .arg("/x")
+                .arg(product_code)
+                .spawn()
+                .chain_err(|| ErrorKind::WindowsUninstallMadness));
+        process::exit(0);
+    }
+    
     let ref cargo_home = try!(utils::cargo_home());
 
     if !cargo_home.join(&format!("bin/rustup{}", EXE_SUFFIX)).exists() {
@@ -647,6 +660,36 @@ pub fn uninstall(no_prompt: bool) -> Result<()> {
     process::exit(0);
 }
 
+#[cfg(not(feature = "msi-installed"))]
+fn get_msi_product_code() -> Result<String> {
+    unreachable!()
+}
+
+#[cfg(feature = "msi-installed")]
+fn get_msi_product_code() -> Result<String> {
+    use winreg::RegKey;
+    use winapi::*;
+
+    let root = RegKey::predef(HKEY_CURRENT_USER);
+    let environment = root.open_subkey_with_flags("SOFTWARE\\rustup", KEY_READ);
+
+    match environment {
+        Ok(env) => {
+            match env.get_value("InstalledProductCode") {
+                Ok(val) => {
+                    Ok(val)
+                }
+                Err(e) => {
+                    Err(e).chain_err(|| ErrorKind::WindowsUninstallMadness)
+                }
+            }
+        }
+        Err(e) => {
+            Err(e).chain_err(|| ErrorKind::WindowsUninstallMadness)
+        }
+    }
+}
+
 #[cfg(unix)]
 fn delete_rustup_and_cargo_home() -> Result<()> {
     let ref cargo_home = try!(utils::cargo_home());