From f082eb6d4aded355ac70566a252a9e97a653292e Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 27 Jun 2022 22:26:26 -0500
Subject: [PATCH 1/2] test(parser): Verify global/default interaction

---
 tests/builder/global_args.rs | 37 ++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/tests/builder/global_args.rs b/tests/builder/global_args.rs
index 2e233b0d457..f3419426bb5 100644
--- a/tests/builder/global_args.rs
+++ b/tests/builder/global_args.rs
@@ -126,3 +126,40 @@ fn deeply_nested_discovery() {
     let m = m.subcommand_matches("c").unwrap();
     assert!(*m.get_one::<bool>("long-c").expect("defaulted by clap"));
 }
+
+#[test]
+fn global_overrides_default() {
+    let cmd = Command::new("test")
+        .arg(
+            Arg::new("name")
+                .long("name")
+                .global(true)
+                .takes_value(true)
+                .default_value("from_default"),
+        )
+        .subcommand(Command::new("sub"));
+
+    let m = cmd.clone().try_get_matches_from(["test"]).unwrap();
+    assert_eq!(
+        m.get_one::<String>("name").unwrap().as_str(),
+        "from_default"
+    );
+
+    let m = cmd
+        .clone()
+        .try_get_matches_from(["test", "--name", "from_arg"])
+        .unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
+
+    let m = cmd
+        .clone()
+        .try_get_matches_from(["test", "--name", "from_arg", "sub"])
+        .unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
+
+    let m = cmd
+        .clone()
+        .try_get_matches_from(["test", "sub", "--name", "from_arg"])
+        .unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
+}

From 72d206e4d90e39e106965c8cf0c10e1e6a8f88c7 Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Mon, 27 Jun 2022 22:36:14 -0500
Subject: [PATCH 2/2] fix(parser): Ensure globals override env vars

This fixes a bug introduced in 4a694f3592b702f86c7a6846b867b61d9feff5fe
when we were trying to move away from presence checks via occurrences.
I switched it to the common type of presence check but really what we
want is a highest-precedence check.

Fixes #3872
---
 src/parser/arg_matcher.rs    |  4 +---
 tests/builder/global_args.rs | 37 ++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/src/parser/arg_matcher.rs b/src/parser/arg_matcher.rs
index 8d15c5799f4..22087e72201 100644
--- a/src/parser/arg_matcher.rs
+++ b/src/parser/arg_matcher.rs
@@ -74,9 +74,7 @@ impl ArgMatcher {
                 // a default value of `other` myprog would have an existing MatchedArg for
                 // `--global-arg` where the value is `other`
                 let to_update = if let Some(parent_ma) = vals_map.get(global_arg) {
-                    if parent_ma.check_explicit(ArgPredicate::IsPresent)
-                        && !ma.check_explicit(ArgPredicate::IsPresent)
-                    {
+                    if parent_ma.source() > ma.source() {
                         parent_ma
                     } else {
                         ma
diff --git a/tests/builder/global_args.rs b/tests/builder/global_args.rs
index f3419426bb5..2f9833bb911 100644
--- a/tests/builder/global_args.rs
+++ b/tests/builder/global_args.rs
@@ -163,3 +163,40 @@ fn global_overrides_default() {
         .unwrap();
     assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
 }
+
+#[test]
+#[cfg(feature = "env")]
+fn global_overrides_env() {
+    std::env::set_var("GLOBAL_OVERRIDES_ENV", "from_env");
+
+    let cmd = Command::new("test")
+        .arg(
+            Arg::new("name")
+                .long("name")
+                .global(true)
+                .takes_value(true)
+                .env("GLOBAL_OVERRIDES_ENV"),
+        )
+        .subcommand(Command::new("sub"));
+
+    let m = cmd.clone().try_get_matches_from(["test"]).unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_env");
+
+    let m = cmd
+        .clone()
+        .try_get_matches_from(["test", "--name", "from_arg"])
+        .unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
+
+    let m = cmd
+        .clone()
+        .try_get_matches_from(["test", "--name", "from_arg", "sub"])
+        .unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
+
+    let m = cmd
+        .clone()
+        .try_get_matches_from(["test", "sub", "--name", "from_arg"])
+        .unwrap();
+    assert_eq!(m.get_one::<String>("name").unwrap().as_str(), "from_arg");
+}