From 8be4fb61d0fbb3734a6b641af985da7dc350d2ec Mon Sep 17 00:00:00 2001
From: Zack Radisic <56137411+zackradisic@users.noreply.github.com>
Date: Wed, 10 Sep 2025 21:33:40 -0700
Subject: [PATCH] make it better

---
 src/bake/DevServer.zig                      |  2 +-
 src/bun.js/api/server/AnyRequestContext.zig | 16 +++++++--------
 src/bun.js/api/server/RequestContext.zig    | 22 +++++++++++++++++----
 3 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/src/bake/DevServer.zig b/src/bake/DevServer.zig
index 77745de49b..1304a99608 100644
--- a/src/bake/DevServer.zig
+++ b/src/bake/DevServer.zig
@@ -1116,7 +1116,7 @@ fn deferRequest(
                     },
                     .saved => |saved| saved,
                 };
-                server_handler.ctx.setAbortCallback(DeferredRequest.onAbortWrapper, &deferred.data);
+                server_handler.ctx.setAdditionalOnAbortCallback(.{ .cb = DeferredRequest.onAbortWrapper, .data = &deferred.data });
                 break :brk .{
                     .server_handler = server_handler,
                 };
diff --git a/src/bun.js/api/server/AnyRequestContext.zig b/src/bun.js/api/server/AnyRequestContext.zig
index 51c3448b5e..9b777a2e6f 100644
--- a/src/bun.js/api/server/AnyRequestContext.zig
+++ b/src/bun.js/api/server/AnyRequestContext.zig
@@ -18,27 +18,23 @@ pub fn init(request_ctx: anytype) AnyRequestContext {
     return .{ .tagged_pointer = Pointer.init(request_ctx) };
 }
 
-pub fn setAbortCallback(self: AnyRequestContext, cb: *const fn (this: *anyopaque) void, data: *anyopaque) void {
+pub fn setAdditionalOnAbortCallback(self: AnyRequestContext, cb: ?AdditionalOnAbortCallback) void {
     if (self.tagged_pointer.isNull()) {
         return;
     }
 
     switch (self.tagged_pointer.tag()) {
         @field(Pointer.Tag, bun.meta.typeBaseName(@typeName(HTTPServer.RequestContext))) => {
-            self.tagged_pointer.as(HTTPServer.RequestContext).onAbortCb = cb;
-            self.tagged_pointer.as(HTTPServer.RequestContext).onAbortData = data;
+            self.tagged_pointer.as(HTTPServer.RequestContext).additional_on_abort = cb;
         },
         @field(Pointer.Tag, bun.meta.typeBaseName(@typeName(HTTPSServer.RequestContext))) => {
-            self.tagged_pointer.as(HTTPSServer.RequestContext).onAbortCb = cb;
-            self.tagged_pointer.as(HTTPSServer.RequestContext).onAbortData = data;
+            self.tagged_pointer.as(HTTPSServer.RequestContext).additional_on_abort = cb;
         },
         @field(Pointer.Tag, bun.meta.typeBaseName(@typeName(DebugHTTPServer.RequestContext))) => {
-            self.tagged_pointer.as(DebugHTTPServer.RequestContext).onAbortCb = cb;
-            self.tagged_pointer.as(DebugHTTPServer.RequestContext).onAbortData = data;
+            self.tagged_pointer.as(DebugHTTPServer.RequestContext).additional_on_abort = cb;
         },
         @field(Pointer.Tag, bun.meta.typeBaseName(@typeName(DebugHTTPSServer.RequestContext))) => {
-            self.tagged_pointer.as(DebugHTTPSServer.RequestContext).onAbortCb = cb;
-            self.tagged_pointer.as(DebugHTTPSServer.RequestContext).onAbortData = data;
+            self.tagged_pointer.as(DebugHTTPSServer.RequestContext).additional_on_abort = cb;
         },
         else => @panic("Unexpected AnyRequestContext tag"),
     }
@@ -277,3 +273,5 @@ const DebugHTTPSServer = bun.api.DebugHTTPSServer;
 const DebugHTTPServer = bun.api.DebugHTTPServer;
 const HTTPSServer = bun.api.HTTPSServer;
 const HTTPServer = bun.api.HTTPServer;
+
+pub const AdditionalOnAbortCallback = @import("./RequestContext.zig").AdditionalOnAbortCallback;
diff --git a/src/bun.js/api/server/RequestContext.zig b/src/bun.js/api/server/RequestContext.zig
index 49b7edff43..1fb30d3e16 100644
--- a/src/bun.js/api/server/RequestContext.zig
+++ b/src/bun.js/api/server/RequestContext.zig
@@ -1,3 +1,18 @@
+/// Q: Why is this needed?
+/// A: The dev server needs to attach its own callback when the request is
+///    aborted.
+///
+/// Q: Why can't the dev server just call `.setAbortHandler(...)` then?
+/// A: It can't, because that is *already* called by the RequestContext, setting
+///    the callback and the user data context pointer.
+///
+///    If it did, it would *overwrite* the user data context pointer (this
+///    is what it did before), causing segfaults.
+pub const AdditionalOnAbortCallback = struct {
+    cb: *const fn (this: *anyopaque) void,
+    data: *anyopaque,
+};
+
 pub fn NewRequestContext(comptime ssl_enabled: bool, comptime debug_mode: bool, comptime ThisServer: type) type {
     return struct {
         const RequestContext = @This();
@@ -55,8 +70,7 @@ pub fn NewRequestContext(comptime ssl_enabled: bool, comptime debug_mode: bool,
         /// Defer finalization until after the request handler task is completed?
         defer_deinit_until_callback_completes: ?*bool = null,
 
-        onAbortCb: ?*const fn (this: *anyopaque) void = null,
-        onAbortData: ?*anyopaque = null,
+        additional_on_abort: ?AdditionalOnAbortCallback = null,
 
         // TODO: support builtin compression
         const can_sendfile = !ssl_enabled and !Environment.isWindows;
@@ -584,8 +598,8 @@ pub fn NewRequestContext(comptime ssl_enabled: bool, comptime debug_mode: bool,
             assert(this.server != null);
             // mark request as aborted
             this.flags.aborted = true;
-            if (this.onAbortData != null and this.onAbortCb != null) {
-                this.onAbortCb.?(this.onAbortData.?);
+            if (this.additional_on_abort) |abort| {
+                abort.cb(abort.data);
             }
 
             this.detachResponse();