Enhance and use code to add an entry to the installed programs on win…

…dows

src/cli/self_update.rs

@@ -344,6 +344,8 @@ pub fn install(
 
         if !opts.no_modify_path {
             do_add_to_path()?;
+            #[cfg(windows)]
+            do_add_to_programs()?;
         }
         utils::create_rustup_home()?;
         maybe_install_rust(
@@ -854,6 +856,8 @@ pub fn uninstall(no_prompt: bool) -> Result<utils::ExitCode> {
 
     // Remove CARGO_HOME/bin from PATH
     do_remove_from_path()?;
+    #[cfg(windows)]
+    do_remove_from_programs()?;
 
     // Delete everything in CARGO_HOME *except* the rustup bin
 

src/cli/self_update/windows.rs

@@ -1,6 +1,6 @@
 use std::env::consts::EXE_SUFFIX;
 use std::ffi::{OsStr, OsString};
-use std::os::windows::ffi::OsStrExt;
+use std::os::windows::ffi::{OsStrExt, OsStringExt};
 use std::path::Path;
 use std::process::Command;
 
@@ -282,12 +282,26 @@ pub fn do_remove_from_path() -> Result<()> {
     _apply_new_path(new_path)
 }
 
-fn do_add_to_programs() -> Result<()> {
+pub fn do_add_to_programs() -> Result<()> {
+    use std::path::PathBuf;
+
     let key = RegKey::predef(HKEY_CURRENT_USER)
         .create_subkey(r"Software\Microsoft\Windows\CurrentVersion\Uninstall\rustup")
         .chain_err(|| ErrorKind::PermissionDenied)?
         .0;
 
+    // Don't overwrite registry if rustup is already installed
+    let prev = key
+        .get_raw_value("UninstallString")
+        .map(|val| from_winreg_value(&val));
+    if let Ok(Some(s)) = prev {
+        let mut path = PathBuf::from(OsString::from_wide(&s));
+        path.pop();
+        if path.exists() {
+            return Ok(());
+        }
+    }
+
     let mut path = utils::cargo_home()?;
     path.push("bin\rustup.exe");
     let mut uninstall_cmd = path.into_os_string();
@@ -300,15 +314,37 @@ fn do_add_to_programs() -> Result<()> {
 
     key.set_raw_value("UninstallString", &reg_value)
         .chain_err(|| ErrorKind::PermissionDenied)?;
-    key.set_value("DisplayName", &"rustup")
+    key.set_value("DisplayName", &"rustup - Rust toolchain manager")
         .chain_err(|| ErrorKind::PermissionDenied)?;
 
     Ok(())
 }
 
-fn do_remove_from_programs() -> Result<()> {
-    RegKey::predef(HKEY_CURRENT_USER)
-        .delete_subkey_all(r"Software\Microsoft\Windows\CurrentVersion\Uninstall\rustup")
+pub fn do_remove_from_programs() -> Result<()> {
+    let root = RegKey::predef(HKEY_CURRENT_USER);
+
+    let key = match root.open_subkey(r"Software\Microsoft\Windows\CurrentVersion\Uninstall\rustup")
+    {
+        Ok(key) => key,
+        Err(ref e) if e.kind() == io::ErrorKind::NotFound => return Ok(()),
+        Err(e) => return Err(e).chain_err(|| ErrorKind::PermissionDenied),
+    };
+
+    // Don't remove uninstall information from another installation
+    let cur = key
+        .get_raw_value("UninstallString")
+        .map(|val| from_winreg_value(&val));
+    if let Ok(Some(s)) = cur {
+        let mut reg_path = PathBuf::from(OsString::from_wide(&s));
+        reg_path.pop();
+        let mut path = utils::cargo_home()?;
+        path.push("bin");
+        if reg_path != path {
+            return Ok(());
+        }
+    }
+
+    root.delete_subkey_all(r"Software\Microsoft\Windows\CurrentVersion\Uninstall\rustup")
         .chain_err(|| ErrorKind::PermissionDenied)
 }