From ba4d9fd9339a7db7705f00ab4a1310b43970a8e2 Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Tue, 3 Oct 2017 08:44:27 -0700
Subject: [PATCH] Set $HOSTNAME in adbd.

bash sets this itself, but mksh doesn't.

This also makes interactive and non-interactive adb shells more similar,
because when we set this in mkshrc that wouldn't affect non-interactive
shells. (I'm not sure whether this is an improvement or not.)

This is certainly _cheaper_ than doing this in mkshrc by calling out to
getprop though.

Bug: N/A
Test: `adb shell printenv` and `adb shell`, `printenv`
Change-Id: I3ff724f19a5098313df83836253f1f7e7872d6a4
---
 adb/shell_service.cpp | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/adb/shell_service.cpp b/adb/shell_service.cpp
index 5b48da029..0c7e1f99b 100644
--- a/adb/shell_service.cpp
+++ b/adb/shell_service.cpp
@@ -95,6 +95,7 @@
 #include <vector>
 
 #include <android-base/logging.h>
+#include <android-base/properties.h>
 #include <android-base/stringprintf.h>
 #include <private/android_logger.h>
 
@@ -212,6 +213,13 @@ Subprocess::~Subprocess() {
     WaitForExit();
 }
 
+static std::string GetHostName() {
+    char buf[HOST_NAME_MAX];
+    if (gethostname(buf, sizeof(buf)) != -1 && strcmp(buf, "localhost") != 0) return buf;
+
+    return android::base::GetProperty("ro.product.device", "android");
+}
+
 bool Subprocess::ForkAndExec(std::string* error) {
     unique_fd child_stdinout_sfd, child_stderr_sfd;
     unique_fd parent_error_sfd, child_error_sfd;
@@ -250,11 +258,11 @@ bool Subprocess::ForkAndExec(std::string* error) {
     }
 
     if (pw != nullptr) {
-        // TODO: $HOSTNAME? Normally bash automatically sets that, but mksh doesn't.
         env["HOME"] = pw->pw_dir;
+        env["HOSTNAME"] = GetHostName();
         env["LOGNAME"] = pw->pw_name;
-        env["USER"] = pw->pw_name;
         env["SHELL"] = pw->pw_shell;
+        env["USER"] = pw->pw_name;
     }
 
     if (!terminal_type_.empty()) {