From 719f80c649b64b746c83439836d7d39c704fc8e7 Mon Sep 17 00:00:00 2001
From: Max Kellermann <mk@cm4all.com>
Date: Mon, 23 Oct 2023 12:14:15 +0200
Subject: [PATCH] spawn/IProtocol: add EXEC_PATH

The `exec_path` field never worked because it was never copied to the
server.
---
 src/spawn/Client.cxx    | 2 ++
 src/spawn/IProtocol.hxx | 1 +
 src/spawn/Server.cxx    | 4 ++++
 3 files changed, 7 insertions(+)

diff --git a/src/spawn/Client.cxx b/src/spawn/Client.cxx
index a4ecbcb6c..636147cb9 100644
--- a/src/spawn/Client.cxx
+++ b/src/spawn/Client.cxx
@@ -277,6 +277,8 @@ Serialize(SpawnSerializer &s, const PreparedChildProcess &p)
 
 	s.WriteOptionalString(SpawnExecCommand::HOOK_INFO, p.hook_info);
 
+	s.WriteOptionalString(SpawnExecCommand::EXEC_PATH, p.exec_path);
+
 	for (const char *i : p.args)
 		s.WriteString(SpawnExecCommand::ARG, i);
 
diff --git a/src/spawn/IProtocol.hxx b/src/spawn/IProtocol.hxx
index 358a53dc0..f1b6ddacc 100644
--- a/src/spawn/IProtocol.hxx
+++ b/src/spawn/IProtocol.hxx
@@ -21,6 +21,7 @@ enum class SpawnRequestCommand : uint8_t {
 };
 
 enum class SpawnExecCommand : uint8_t {
+	EXEC_PATH,
 	ARG,
 	SETENV,
 	UMASK,
diff --git a/src/spawn/Server.cxx b/src/spawn/Server.cxx
index 577c06222..54a03c8b7 100644
--- a/src/spawn/Server.cxx
+++ b/src/spawn/Server.cxx
@@ -511,6 +511,10 @@ SpawnServerConnection::HandleExecMessage(SpawnPayload payload,
 	while (!payload.empty()) {
 		const SpawnExecCommand cmd = (SpawnExecCommand)payload.ReadByte();
 		switch (cmd) {
+		case SpawnExecCommand::EXEC_PATH:
+			p.exec_path = payload.ReadString();
+			break;
+
 		case SpawnExecCommand::ARG:
 			if (p.args.size() >= 16384)
 				throw MalformedSpawnPayloadError();