Fix: AOT get_headers insert-block restore (#27317)

lib/JIT/Builtin/GetHeadersRuntime.php

@@ -4,6 +4,7 @@
 
 namespace PHPCompiler\JIT\Builtin;
 
+use PHPCompiler\JIT\BasicBlockHelper;
 use PHPCompiler\JIT\Context;
 use PHPCompiler\JIT\JitNestedHelperCoerce;
 use PHPCompiler\JIT\JitVmHelperLink;
@@ -13,6 +14,8 @@
  * JIT/AOT link for __compiler_get_headers via GetHeadersJitHelper PHP (#9212, #24633).
  *
  * Helper compile: {@see JitVmHelperLink::ensureCompiled} (peer StreamFstat #24586 / StringQuotPrint #24620).
+ * Call-site {@see ensureLinked} restores the caller insert block after bridge emit
+ * (thin AOT: "Current basic block has no parent function", #27317 / peer #27088).
  * SSOT {@see \PHPCompiler\ext\standard\VmHttpFetchNative} / {@see \PHPCompiler\ext\standard\VmHttpHeaders}.
  * php-src: ext/standard/head.c — PHP_FUNCTION(get_headers)
  */
@@ -43,10 +46,16 @@ public static function implement(Context $context): void
             return;
         }
 
+        // Preserve caller insert block — clearInsertionPosition alone orphans mid-emit (#27317 / #27088).
+        $savedInsert = BasicBlockHelper::tryGetInsertBlock($context);
         self::ensureJitHelperCompiled($context);
         self::implementGetHeadersBridge($context);
         self::registerLinkedRuntime($context);
-        $context->builder->clearInsertionPosition();
+        if (null !== $savedInsert) {
+            BasicBlockHelper::restoreInsertBlock($context, $savedInsert);
+        } else {
+            $context->builder->clearInsertionPosition();
+        }
     }
 
     private static function implementGetHeadersBridge(Context $context): void

test/fixtures/aot/cases/get_headers_refused_connection.phpt

@@ -0,0 +1,7 @@
+--TEST--
+AOT get_headers() refused connection returns false (#27317, ext/standard/head.c)
+--FILE--
+<?php
+echo var_export(@get_headers('http://127.0.0.1:1/') === false, true), "\n";
+--EXPECT--
+true

test/repro/maintainer_gap_aot_get_headers.php

@@ -0,0 +1,15 @@
+<?php
+/**
+ * Maintainer gap — AOT get_headers() compile fails (ext/standard/head.c).
+ *
+ * Zend/VM/JIT: false for refused connection (with @).
+ * AOT: compile aborts — "Current basic block has no parent function".
+ *
+ * php-src: ext/standard/head.c — PHP_FUNCTION(get_headers)
+ *
+ * Run:
+ *   php bin/vm.php test/repro/maintainer_gap_aot_get_headers.php
+ *   php bin/jit.php test/repro/maintainer_gap_aot_get_headers.php
+ *   php bin/compile.php test/repro/maintainer_gap_aot_get_headers.php -o /tmp/get_headers_aot
+ */
+echo var_export(@get_headers('http://127.0.0.1:1/') === false, true), "\n";

test/unit/GetHeadersJitRuntimeShrinkTest.php

@@ -22,14 +22,15 @@ public function testGetHeadersRuntimeRoutesThroughGetHeadersJitHelper(): void
         $this->assertStringContainsString('GetHeadersJitHelper', $source);
         $this->assertStringContainsString('JitVmHelperLink::ensureCompiled', $source);
         $this->assertStringContainsString('JitVmHelperLink::lookupCompiled', $source);
+        $this->assertStringContainsString('BasicBlockHelper::restoreInsertBlock', $source);
         $this->assertStringNotContainsString('VmHttpFetchPure::request', $source);
         $this->assertStringNotContainsString('NestedJitCompileScope::run', $source);
         $this->assertStringNotContainsString('parseAndCompile', $source);
         $this->assertStringNotContainsString('new JIT(', $source);
         $this->assertStringNotContainsString('use PHPCompiler\\JIT;', $source);
 
         $lineCount = \substr_count($source, "\n");
-        $this->assertLessThan(120, $lineCount, 'GetHeadersRuntime must be a thin bridge');
+        $this->assertLessThan(130, $lineCount, 'GetHeadersRuntime must be a thin bridge');
     }
 
     public function testJitGetHeadersUsesCompilerGetHeadersAbi(): void