From d5a7c459662a4868f4a38cbafb72dce7885e027d Mon Sep 17 00:00:00 2001
From: Evan Jones <evan.jones@datadoghq.com>
Date: Fri, 9 Aug 2024 14:26:18 -0400
Subject: [PATCH 1/2] doc: std::env::var: Returns None for names with '=' or
 NUL byte

The documentation incorrectly stated that std::env::var could return
an error for variable names containing '=' or the NUL byte. Copy the
correct documentation from var_os.

var_os was fixed in Commit 8a7a665, Pull Request #109894, which
closed Issue #109893.

This documentation was incorrectly added in commit f2c0f292, which
replaced a panic in var_os by returning None, but documented the
change as "May error if ...".

Reference the specific error values and link to them.
---
 library/std/src/env.rs | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 50ae83090c7..215b7b03f04 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -198,13 +198,16 @@ impl fmt::Debug for VarsOs {
 ///
 /// # Errors
 ///
-/// This function will return an error if the environment variable isn't set.
+/// This function returns [`VarError::NotPresent`] if the environment variable
+/// isn't set.
 ///
-/// This function may return an error if the environment variable's name contains
-/// the equal sign character (`=`) or the NUL character.
+/// This function may return [`VarError::NotPresent`] if the
+/// environment variable's name contains the equal sign character (`=`) or the
+/// NUL character.
 ///
-/// This function will return an error if the environment variable's value is
-/// not valid Unicode. If this is not desired, consider using [`var_os`].
+/// This function will return [`VarError::NotUnicode`] if the environment
+/// variable's value is not valid Unicode. If this is not desired, consider
+/// using [`var_os`].
 ///
 /// # Examples
 ///

From b0023f5a417374aad980422b3f437f133676d4ef Mon Sep 17 00:00:00 2001
From: Evan Jones <ej@evanjones.ca>
Date: Sun, 18 Aug 2024 10:43:36 -0400
Subject: [PATCH 2/2] code review improvements

---
 library/std/src/env.rs | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 215b7b03f04..bbe191181c5 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -198,16 +198,12 @@ impl fmt::Debug for VarsOs {
 ///
 /// # Errors
 ///
-/// This function returns [`VarError::NotPresent`] if the environment variable
-/// isn't set.
+/// Returns [`VarError::NotPresent`] if:
+/// - The variable is not set.
+/// - The variable's name contains an equal sign or NUL (`'='` or `'\0'`).
 ///
-/// This function may return [`VarError::NotPresent`] if the
-/// environment variable's name contains the equal sign character (`=`) or the
-/// NUL character.
-///
-/// This function will return [`VarError::NotUnicode`] if the environment
-/// variable's value is not valid Unicode. If this is not desired, consider
-/// using [`var_os`].
+/// Returns [`VarError::NotUnicode`] if the variable's value is not valid
+/// Unicode. If this is not desired, consider using [`var_os`].
 ///
 /// # Examples
 ///