From c1a2ac7fa4c94cfdce312ccdb5cb8773cb75bbcc Mon Sep 17 00:00:00 2001
From: Weihang Lo <me@weihanglo.tw>
Date: Wed, 14 Sep 2022 18:38:41 +0100
Subject: [PATCH] Make `cargo version` work even with malformed configurations

---
 src/bin/cargo/cli.rs | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/bin/cargo/cli.rs b/src/bin/cargo/cli.rs
index 00e528d80f7a..2f1ebffe547b 100644
--- a/src/bin/cargo/cli.rs
+++ b/src/bin/cargo/cli.rs
@@ -30,9 +30,6 @@ pub fn main(config: &mut LazyConfig) -> CliResult {
     // the [alias] table).
     let config = config.get_mut();
 
-    // Global args need to be extracted before expanding aliases because the
-    // clap code for extracting a subcommand discards global options
-    // (appearing before the subcommand).
     let (expanded_args, global_args) = expand_aliases(config, args, vec![])?;
 
     if expanded_args
@@ -222,16 +219,30 @@ fn add_ssl(version_string: &mut String) {
     }
 }
 
+/// Expands aliases recursively to collect all the command line arguments.
+///
+/// [`GlobalArgs`] need to be extracted before expanding aliases because the
+/// clap code for extracting a subcommand discards global options
+/// (appearing before the subcommand).
 fn expand_aliases(
     config: &mut Config,
     args: ArgMatches,
     mut already_expanded: Vec<String>,
 ) -> Result<(ArgMatches, GlobalArgs), CliError> {
     if let Some((cmd, args)) = args.subcommand() {
-        match (
-            commands::builtin_exec(cmd),
-            super::aliased_command(config, cmd)?,
-        ) {
+        let exec = commands::builtin_exec(cmd);
+        let aliased_cmd = super::aliased_command(config, cmd).or_else(|e| {
+            // HACK: `cargo version` must always work even with malformed configs.
+            // Here we treat the error as the aliased command not found, 
+            // so it falls back to call builtin `cargo version`
+            if cmd == "version" {
+                Ok(None)
+            } else {
+                Err(e)
+            }
+        })?;
+
+        match (exec, aliased_cmd) {
             (Some(_), Some(_)) => {
                 // User alias conflicts with a built-in subcommand
                 config.shell().warn(format!(