From 79d0647d1935815a18aa72982f57078df7104ffe Mon Sep 17 00:00:00 2001
From: orklah <ronan_morin@hotmail.com>
Date: Sat, 17 Jul 2021 22:00:54 +0200
Subject: [PATCH 1/3] fix issue when setting a value to a global is considered
 unused

---
 src/Psalm/Context.php                                     | 5 +++++
 src/Psalm/Internal/Analyzer/Statements/GlobalAnalyzer.php | 1 +
 src/Psalm/Internal/Analyzer/StatementsAnalyzer.php        | 5 +++--
 tests/UnusedVariableTest.php                              | 8 ++++++++
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/Psalm/Context.php b/src/Psalm/Context.php
index 1101b8fe555..ab482acac32 100644
--- a/src/Psalm/Context.php
+++ b/src/Psalm/Context.php
@@ -367,6 +367,11 @@ class Context
      */
     public $has_returned = false;
 
+    /**
+     * @var array<string, bool>
+     */
+    public $vars_from_global;
+
     public function __construct(?string $self = null)
     {
         $this->self = $self;
diff --git a/src/Psalm/Internal/Analyzer/Statements/GlobalAnalyzer.php b/src/Psalm/Internal/Analyzer/Statements/GlobalAnalyzer.php
index dc27c13ae0e..6ebb3d34beb 100644
--- a/src/Psalm/Internal/Analyzer/Statements/GlobalAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/Statements/GlobalAnalyzer.php
@@ -65,6 +65,7 @@ public static function analyze(
                     $context->vars_in_scope[$var_id]->parent_nodes = [
                         $assignment_node->id => $assignment_node,
                     ];
+                    $context->vars_from_global[$var_id] = true;
                     $statements_analyzer->registerVariable(
                         $var_id,
                         new CodeLocation($statements_analyzer, $var),
diff --git a/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php b/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
index fd154f7a663..034ee5baefd 100644
--- a/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
+++ b/src/Psalm/Internal/Analyzer/StatementsAnalyzer.php
@@ -194,7 +194,7 @@ public function analyze(
             && $context->check_variables
         ) {
             //var_dump($this->data_flow_graph);
-            $this->checkUnreferencedVars($stmts);
+            $this->checkUnreferencedVars($stmts, $context);
         }
 
         if ($codebase->alter_code && $root_scope && $this->vars_to_initialize) {
@@ -701,7 +701,7 @@ private function parseStatementDocblock(
     /**
      * @param  array<PhpParser\Node\Stmt>   $stmts
      */
-    public function checkUnreferencedVars(array $stmts): void
+    public function checkUnreferencedVars(array $stmts, Context $context): void
     {
         $source = $this->getSource();
         $codebase = $source->getCodebase();
@@ -776,6 +776,7 @@ public function checkUnreferencedVars(array $stmts): void
             $assignment_node = DataFlowNode::getForAssignment($var_id, $original_location);
 
             if (!isset($this->byref_uses[$var_id])
+                && !isset($context->vars_from_global[$var_id])
                 && !VariableFetchAnalyzer::isSuperGlobal($var_id)
                 && $this->data_flow_graph instanceof VariableUseGraph
                 && !$this->data_flow_graph->isVariableUsed($assignment_node)
diff --git a/tests/UnusedVariableTest.php b/tests/UnusedVariableTest.php
index 6e4790a2b81..1fe4755baba 100644
--- a/tests/UnusedVariableTest.php
+++ b/tests/UnusedVariableTest.php
@@ -2424,6 +2424,14 @@ function randomBits() : string
                         return $randomBytes;
                     }'
             ],
+            'globalChangeValue' => [
+                '<?php
+                    function setProxySettingsFromEnv(): void {
+                        global $a;
+
+                        $a = false;
+                    }'
+            ],
         ];
     }
 

From fcbd443bc80f2556a137884389bfa0cbf89fa7bb Mon Sep 17 00:00:00 2001
From: orklah <ronan_morin@hotmail.com>
Date: Sat, 17 Jul 2021 22:04:22 +0200
Subject: [PATCH 2/3] initialize array

---
 src/Psalm/Context.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Psalm/Context.php b/src/Psalm/Context.php
index ab482acac32..7531fcbd4a8 100644
--- a/src/Psalm/Context.php
+++ b/src/Psalm/Context.php
@@ -370,7 +370,7 @@ class Context
     /**
      * @var array<string, bool>
      */
-    public $vars_from_global;
+    public $vars_from_global = [];
 
     public function __construct(?string $self = null)
     {

From d1a4975e3dec8c38840ee88b014ecf61fcce5079 Mon Sep 17 00:00:00 2001
From: orklah <ronan_morin@hotmail.com>
Date: Sat, 17 Jul 2021 23:20:13 +0200
Subject: [PATCH 3/3] remove test no longer applicable

---
 tests/UnusedVariableTest.php | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/tests/UnusedVariableTest.php b/tests/UnusedVariableTest.php
index 1fe4755baba..f9235c698b3 100644
--- a/tests/UnusedVariableTest.php
+++ b/tests/UnusedVariableTest.php
@@ -3269,15 +3269,6 @@ function foo($mixed_or_null): Exception {
                     };',
                 'error_message' => 'UnusedVariable',
             ],
-            'globalVariableUsage' => [
-                '<?php
-                    $a = "hello";
-                    function example() : void {
-                        global $a;
-                    }
-                    example();',
-                'error_message' => 'UnusedVariable',
-            ],
             'warnAboutOriginalBadArray' => [
                 '<?php
                     function takesArray(array $arr) : void {