1 files changed, 35 insertions, 13 deletions

diff --git a/cli/tools/upgrade.rs b/cli/tools/upgrade.rs
index 0861d1f49..8c987e82c 100644
--- a/cli/tools/upgrade.rs
+++ b/cli/tools/upgrade.rs
@@ -8,6 +8,7 @@ use crate::util::progress_bar::ProgressBar;
 use crate::version;
 
 use deno_core::anyhow::bail;
+use deno_core::anyhow::Context;
 use deno_core::error::AnyError;
 use deno_core::futures::future::BoxFuture;
 use deno_core::futures::FutureExt;
@@ -234,14 +235,14 @@ async fn fetch_and_store_latest_version<
 }
 
 pub async fn upgrade(upgrade_flags: UpgradeFlags) -> Result<(), AnyError> {
-  let old_exe_path = std::env::current_exe()?;
-  let metadata = fs::metadata(&old_exe_path)?;
+  let current_exe_path = std::env::current_exe()?;
+  let metadata = fs::metadata(&current_exe_path)?;
   let permissions = metadata.permissions();
 
   if permissions.readonly() {
     bail!(
       "You do not have write permission to {}",
-      old_exe_path.display()
+      current_exe_path.display()
     );
   }
   #[cfg(unix)]
@@ -252,7 +253,7 @@ pub async fn upgrade(upgrade_flags: UpgradeFlags) -> Result<(), AnyError> {
       "You don't have write permission to {} because it's owned by root.\n",
       "Consider updating deno through your package manager if its installed from it.\n",
       "Otherwise run `deno upgrade` as root.",
-    ), old_exe_path.display());
+    ), current_exe_path.display());
   }
 
   let client = build_http_client(upgrade_flags.ca_file)?;
@@ -348,12 +349,33 @@ pub async fn upgrade(upgrade_flags: UpgradeFlags) -> Result<(), AnyError> {
   check_exe(&new_exe_path)?;
 
   if !upgrade_flags.dry_run {
-    match upgrade_flags.output {
-      Some(path) => {
-        fs::rename(&new_exe_path, &path)
-          .or_else(|_| fs::copy(&new_exe_path, &path).map(|_| ()))?;
+    let output_exe_path =
+      upgrade_flags.output.as_ref().unwrap_or(&current_exe_path);
+    let output_result = if *output_exe_path == current_exe_path {
+      replace_exe(&new_exe_path, output_exe_path)
+    } else {
+      fs::rename(&new_exe_path, output_exe_path)
+        .or_else(|_| fs::copy(&new_exe_path, output_exe_path).map(|_| ()))
+    };
+    if let Err(err) = output_result {
+      const WIN_ERROR_ACCESS_DENIED: i32 = 5;
+      if cfg!(windows) && err.raw_os_error() == Some(WIN_ERROR_ACCESS_DENIED) {
+        return Err(err).with_context(|| {
+          format!(
+            concat!(
+              "Access denied: Could not replace the deno executable. This may be ",
+              "because an existing deno process is running. Please ensure there ",
+              "are no running deno processes (ex. Stop-Process -Name deno ; deno {}), ",
+              "close any editors before upgrading, and ensure you have sufficient ",
+              "permission to '{}'."
+            ),
+            std::env::args().collect::<Vec<_>>().join(" "),
+            output_exe_path.display(),
+          )
+        });
+      } else {
+        return Err(err.into());
       }
-      None => replace_exe(&new_exe_path, &old_exe_path)?,
     }
   }
 
@@ -519,17 +541,17 @@ pub fn unpack(
   Ok(exe_path)
 }
 
-fn replace_exe(new: &Path, old: &Path) -> Result<(), std::io::Error> {
+fn replace_exe(from: &Path, to: &Path) -> Result<(), std::io::Error> {
   if cfg!(windows) {
     // On windows you cannot replace the currently running executable.
     // so first we rename it to deno.old.exe
-    fs::rename(old, old.with_extension("old.exe"))?;
+    fs::rename(to, to.with_extension("old.exe"))?;
   } else {
-    fs::remove_file(old)?;
+    fs::remove_file(to)?;
   }
   // Windows cannot rename files across device boundaries, so if rename fails,
   // we try again with copy.
-  fs::rename(new, old).or_else(|_| fs::copy(new, old).map(|_| ()))?;
+  fs::rename(from, to).or_else(|_| fs::copy(from, to).map(|_| ()))?;
   Ok(())
 }