From 55451cc21474ea8f2f862fef80c299b08ddcfc84 Mon Sep 17 00:00:00 2001
From: Michael Carroll <mjcarroll@intrinsic.ai>
Date: Wed, 1 Nov 2023 16:07:56 +0000
Subject: [PATCH] Sort the environment variables

Signed-off-by: Michael Carroll <mjcarroll@intrinsic.ai>
---
 src/Environment.cc      | 10 +++++++++-
 src/Environment_TEST.cc |  3 ++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/Environment.cc b/src/Environment.cc
index 7c2f02f..b18824f 100644
--- a/src/Environment.cc
+++ b/src/Environment.cc
@@ -17,8 +17,10 @@
 
 #include <gz/utils/Environment.hh>
 
+#include <algorithm>
 #include <cstdlib>
 #include <string>
+#include <vector>
 
 extern char ** environ;
 
@@ -165,7 +167,13 @@ bool setenv(const EnvironmentMap &_vars)
 std::string printenv()
 {
   std::string ret;
-  for (const auto &[key, value] : env())
+  // Variables are in an unordered_map as we generally don't
+  // care, but for printing sort for consistent display
+  auto currentEnv = env();
+  auto sorted = std::vector<std::pair<std::string, std::string>>(
+    currentEnv.begin(), currentEnv.end());
+  std::sort(sorted.begin(), sorted.end());
+  for (const auto &[key, value] : sorted)
   {
     ret.append(key);
     ret.append("=");
diff --git a/src/Environment_TEST.cc b/src/Environment_TEST.cc
index 24da134..6d09923 100644
--- a/src/Environment_TEST.cc
+++ b/src/Environment_TEST.cc
@@ -171,6 +171,7 @@ TEST(Environment, printenv)
   ASSERT_TRUE(gz::utils::setenv("GZ_BAR_KEY", "GZ_BAR_VAL"));
   ASSERT_TRUE(gz::utils::setenv("GZ_BAZ_KEY", "GZ_BAZ_VAL"));
 
+  // Always returned in sorted order
   EXPECT_EQ(gz::utils::printenv(),
-    "GZ_BAZ_KEY=GZ_BAZ_VAL\nGZ_BAR_KEY=GZ_BAR_VAL\nGZ_FOO_KEY=GZ_FOO_VAL\n");
+    "GZ_BAR_KEY=GZ_BAR_VAL\nGZ_BAZ_KEY=GZ_BAZ_VAL\nGZ_FOO_KEY=GZ_FOO_VAL\n");
 }