Fix race condition in async cURL error handling test

The test was spawning three async coroutines that executed in parallel,
causing non-deterministic output order. This led to sporadic test failures
when the actual output order differed from the expected order.

Solution:
- Functions now return arrays with numbered keys (1-11) instead of echoing
- After await_all(), all outputs are merged and sorted by key (ksort)
- Output is then printed in deterministic order

This preserves the async nature of the test while ensuring stable output.
The test still validates concurrent cURL operations with proper error handling.

Author: EdmondDantes

tests/curl/005-error_handling.phpt

@@ -12,62 +12,65 @@ use function Async\await_all;
 $server = async_test_server_start();
 
 function test_connection_error() {
-    echo "Testing connection error\n";
-    
+    $output = [];
+    $output[1] = "Testing connection error";
+
     $ch = curl_init();
     curl_setopt($ch, CURLOPT_URL, "http://127.0.0.1:99991/nonexistent"); // Wrong port
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
     curl_setopt($ch, CURLOPT_TIMEOUT, 2);
     curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 1);
-    
+
     $response = curl_exec($ch);
     $error = curl_error($ch);
     $errno = curl_errno($ch);
-    
-    
-    echo "Connection failed as expected\n";
-    echo "Error present: " . (!empty($error) ? "yes" : "no") . "\n";
-    echo "Error number: $errno\n";
-    
-    return $response;
+
+
+    $output[4] = "Connection failed as expected";
+    $output[5] = "Error present: " . (!empty($error) ? "yes" : "no");
+    $output[6] = "Error number: $errno";
+
+    return $output;
 }
 
 function test_server_error($server) {
-    echo "Testing server error\n";
-    
+    $output = [];
+    $output[2] = "Testing server error";
+
     $ch = curl_init();
     curl_setopt($ch, CURLOPT_URL, "http://localhost:{$server->port}/error");
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
     curl_setopt($ch, CURLOPT_TIMEOUT, 5);
-    
+
     $response = curl_exec($ch);
     $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
     $error = curl_error($ch);
-    
-    
-    echo "HTTP Code: $http_code\n";
-    echo "Error: " . ($error ?: "none") . "\n";
-    echo "Response length: " . strlen($response) . "\n";
-    
-    return $response;
+
+
+    $output[7] = "HTTP Code: $http_code";
+    $output[8] = "Error: " . ($error ?: "none");
+    $output[9] = "Response length: " . strlen($response);
+
+    return $output;
 }
 
 function test_not_found($server) {
-    echo "Testing 404 error\n";
-    
+    $output = [];
+    $output[3] = "Testing 404 error";
+
     $ch = curl_init();
     curl_setopt($ch, CURLOPT_URL, "http://localhost:{$server->port}/missing.html");
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
     curl_setopt($ch, CURLOPT_TIMEOUT, 5);
-    
+
     $response = curl_exec($ch);
     $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
-    
-    
-    echo "HTTP Code: $http_code\n";
-    echo "Response length: " . strlen($response) . "\n";
-    
-    return $response;
+
+
+    $output[10] = "HTTP Code: $http_code";
+    $output[11] = "Response length: " . strlen($response);
+
+    return $output;
 }
 
 echo "Test start\n";
@@ -80,6 +83,18 @@ $coroutines = [
 
 $results = await_all($coroutines);
 
+// Merge all outputs and sort by key to ensure deterministic order
+$all_output = [];
+foreach ($results as $output) {
+    $all_output = array_merge($all_output, $output);
+}
+ksort($all_output);
+
+// Print in sorted order
+foreach ($all_output as $line) {
+    echo "$line\n";
+}
+
 echo "Test end\n";
 
 async_test_server_stop($server);