Fix override argument processing bug (#115)

An invocation like `just foo=bar` would lead to no recipe being run due
to the way that override arguments were being processed.

Fix that and add a test that covers that case.

src/app.rs

@@ -265,18 +265,18 @@ pub fn app() {
 
   let override_re = regex::Regex::new("^([^=]+)=(.*)$").unwrap();
 
-  let arguments = if let Some(arguments) = matches.values_of("arguments") {
-    let mut done = false;
-    let mut rest = vec![];
-    for argument in arguments {
-      if !done && override_re.is_match(argument) {
+  let raw_arguments = matches.values_of("arguments").map(|values| values.collect::<Vec<_>>())
+    .unwrap_or_default();
+
+  for argument in raw_arguments.iter().take_while(|arg| override_re.is_match(arg)) {
     let captures = override_re.captures(argument).unwrap();
     overrides.insert(captures.at(1).unwrap(), captures.at(2).unwrap());
-      } else {
-        rest.push(argument);
-        done = true;
-      }
   }
+
+  let rest = raw_arguments.iter().skip_while(|arg| override_re.is_match(arg))
+    .cloned().collect::<Vec<_>>();
+
+  let arguments = if !rest.is_empty() {
     rest
   } else if let Some(recipe) = justfile.first() {
     vec![recipe]

src/integration.rs

@@ -660,6 +660,25 @@ wut:
   );
 }
 
+#[test]
+fn export_override() {
+  integration_test(
+    &["foo=hello", "--set", "bar", "bye"],
+    r#"
+export foo = "a"
+baz = "c"
+export bar = "b"
+export abc = foo + "-" + bar + "-" + baz
+
+wut:
+  echo $foo $bar $abc
+"#,
+    0,
+    "hello bye hello-bye-c\n",
+    "echo $foo $bar $abc\n",
+  );
+}
+
 #[test]
 fn export_shebang() {
   integration_test(