From fae1be9ca6173eda0d3bbde6bedbbff2f922a97f Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Fri, 24 Apr 2026 01:07:10 +0300
Subject: [PATCH] veb: fix veb: segfault when serving static files (fixes
 #26939)

---
 vlib/veb/controller.v                |  7 +++++--
 vlib/veb/tests/static_handler_test.v | 12 ++++++++++++
 vlib/veb/veb.v                       | 12 ++++++++++--
 vlib/veb/veb_fasthttp.v              | 12 ++++++++++--
 4 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/vlib/veb/controller.v b/vlib/veb/controller.v
index f4a7b4841..4668102ce 100644
--- a/vlib/veb/controller.v
+++ b/vlib/veb/controller.v
@@ -58,8 +58,11 @@ pub fn controller[A, X](path string, mut global_app A) !&ControllerPath {
 			user_context.Context = ctx
 
 			handle_route[A, X](mut global_app, mut user_context, url, host, &routes)
-			// we need to explicitly tell the V compiler to return a reference
-			return &user_context.Context
+			// Preserve the handled context on the heap before the stack-local user context goes away.
+			unsafe {
+				*ctx = user_context.Context
+			}
+			return ctx
 		}
 	}
 }
diff --git a/vlib/veb/tests/static_handler_test.v b/vlib/veb/tests/static_handler_test.v
index a2f7f7f23..46673f753 100644
--- a/vlib/veb/tests/static_handler_test.v
+++ b/vlib/veb/tests/static_handler_test.v
@@ -23,6 +23,11 @@ pub fn (mut app App) index(mut ctx Context) veb.Result {
 	return ctx.text('Hello V!')
 }
 
+@['/redirect_root']
+pub fn (mut app App) redirect_root(mut ctx Context) veb.Result {
+	return ctx.redirect('/root.txt')
+}
+
 @[post]
 pub fn (mut app App) post_request(mut ctx Context) veb.Result {
 	return ctx.text(ctx.req.data)
@@ -90,6 +95,13 @@ fn test_static_root() {
 	assert x.body == 'root'
 }
 
+fn test_redirect_to_static_root() {
+	x := http.get('${localserver}/redirect_root')!
+
+	assert x.status() == .ok
+	assert x.body == 'root'
+}
+
 fn test_scans_subdirs() {
 	x := http.get('${localserver}/sub_folder/sub.txt')!
 
diff --git a/vlib/veb/veb.v b/vlib/veb/veb.v
index f63dffc92..1965a699d 100644
--- a/vlib/veb/veb.v
+++ b/vlib/veb/veb.v
@@ -297,7 +297,11 @@ fn handle_ssl_request[A, X](req http.Request, params &SslRequestParams) ?&Contex
 			global_app.static_compression_max_size, global_app.static_compression_mime_types,
 			global_app.enable_markdown_negotiation), mut user_context, url, host)
 		{
-			return &user_context.Context
+			// Preserve the handled context on the heap before the stack-local user context goes away.
+			unsafe {
+				*ctx = user_context.Context
+			}
+			return ctx
 		}
 	}
 	$if A is ControllerInterface {
@@ -308,7 +312,11 @@ fn handle_ssl_request[A, X](req http.Request, params &SslRequestParams) ?&Contex
 	mut user_context := X{}
 	user_context.Context = ctx
 	handle_route[A, X](mut global_app, mut user_context, url, host, params.routes)
-	return &user_context.Context
+	// Preserve the handled context on the heap before the stack-local user context goes away.
+	unsafe {
+		*ctx = user_context.Context
+	}
+	return ctx
 }
 
 fn write_ssl_context_response(mut ssl_conn mbedtls.SSLConn, completed_context &Context) ! {
diff --git a/vlib/veb/veb_fasthttp.v b/vlib/veb/veb_fasthttp.v
index c0b2fa4cc..5c05ceefe 100644
--- a/vlib/veb/veb_fasthttp.v
+++ b/vlib/veb/veb_fasthttp.v
@@ -189,7 +189,11 @@ fn handle_request_and_route[A, X](mut app A, req http.Request, _client_fd int, p
 			app.static_compression_mime_types, app.enable_markdown_negotiation), mut user_context,
 			url, host)
 		{
-			return &user_context.Context
+			// Preserve the handled context on the heap before the stack-local user context goes away.
+			unsafe {
+				*ctx = user_context.Context
+			}
+			return ctx
 		}
 	}
 	// Match controller paths first
@@ -202,7 +206,11 @@ fn handle_request_and_route[A, X](mut app A, req http.Request, _client_fd int, p
 	mut user_context := X{}
 	user_context.Context = ctx
 	handle_route[A, X](mut app, mut user_context, url, host, params.routes)
-	return &user_context.Context
+	// Preserve the handled context on the heap before the stack-local user context goes away.
+	unsafe {
+		*ctx = user_context.Context
+	}
+	return ctx
 }
 
 // decode_chunked_body decodes a chunked transfer-encoded body string
-- 
2.39.5