From 05fb45be17bbdde8977e442633f453d60724845f Mon Sep 17 00:00:00 2001
From: Josh Gao <jmgao@google.com>
Date: Thu, 29 Mar 2018 12:34:28 -0700
Subject: [PATCH] adb: fix FdeventTest.invalid_fd on Windows.

Bail out immediately in our poll emulation if we have any invalid file
descriptors, instead of actually calling WSAPoll (which might block
forever).

Test: wine adb_test.exe
Change-Id: I06ccca305783ee7a1721b1585ddf73e022bd02d7
---
 adb/sysdeps_test.cpp  | 14 ++++++++++++++
 adb/sysdeps_win32.cpp |  8 +++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/adb/sysdeps_test.cpp b/adb/sysdeps_test.cpp
index fd1988252..79cebe6b5 100644
--- a/adb/sysdeps_test.cpp
+++ b/adb/sysdeps_test.cpp
@@ -121,10 +121,13 @@ TEST_F(sysdeps_poll, invalid_fd) {
     adb_pollfd pfd[3] = {};
     pfd[0].fd = fds[0];
     pfd[0].events = POLLRDNORM;
+    pfd[0].revents = ~0;
     pfd[1].fd = INT_MAX;
     pfd[1].events = POLLRDNORM;
+    pfd[1].revents = ~0;
     pfd[2].fd = fds[1];
     pfd[2].events = POLLWRNORM;
+    pfd[2].revents = ~0;
 
     ASSERT_TRUE(WriteFdExactly(fds[1], "foo", 4));
 
@@ -136,6 +139,17 @@ TEST_F(sysdeps_poll, invalid_fd) {
     EXPECT_EQ(POLLRDNORM, pfd[0].revents);
     EXPECT_EQ(POLLNVAL, pfd[1].revents);
     EXPECT_EQ(POLLWRNORM, pfd[2].revents);
+
+    // Make sure that we return immediately if an invalid FD is given.
+    pfd[0].fd = fds[0];
+    pfd[0].events = POLLRDNORM;
+    pfd[0].revents = ~0;
+    pfd[1].fd = INT_MAX;
+    pfd[1].events = POLLRDNORM;
+    pfd[1].revents = ~0;
+    EXPECT_EQ(2, adb_poll(pfd, 2, -1));
+    EXPECT_EQ(POLLRDNORM, pfd[0].revents);
+    EXPECT_EQ(POLLNVAL, pfd[1].revents);
 }
 
 TEST_F(sysdeps_poll, duplicate_fd) {
diff --git a/adb/sysdeps_win32.cpp b/adb/sysdeps_win32.cpp
index 62f4ac831..7d35fb67b 100644
--- a/adb/sysdeps_win32.cpp
+++ b/adb/sysdeps_win32.cpp
@@ -529,6 +529,7 @@ extern int adb_poll(adb_pollfd* fds, size_t nfds, int timeout) {
     int skipped = 0;
     std::vector<WSAPOLLFD> sockets;
     std::vector<adb_pollfd*> original;
+
     for (size_t i = 0; i < nfds; ++i) {
         FH fh = _fh_from_int(fds[i].fd, __func__);
         if (!fh || !fh->used || fh->clazz != &_fh_socket_class) {
@@ -549,6 +550,11 @@ extern int adb_poll(adb_pollfd* fds, size_t nfds, int timeout) {
         return skipped;
     }
 
+    // If we have any invalid FDs in our FD set, make sure to return immediately.
+    if (skipped > 0) {
+        timeout = 0;
+    }
+
     int result = WSAPoll(sockets.data(), sockets.size(), timeout);
     if (result == SOCKET_ERROR) {
         _socket_set_errno(WSAGetLastError());
@@ -560,7 +566,7 @@ extern int adb_poll(adb_pollfd* fds, size_t nfds, int timeout) {
         original[i]->revents = sockets[i].revents;
     }
 
-    // WSAPoll appears to return the number of unique FDs with avaiable events, instead of how many
+    // WSAPoll appears to return the number of unique FDs with available events, instead of how many
     // of the pollfd elements have a non-zero revents field, which is what it and poll are specified
     // to do. Ignore its result and calculate the proper return value.
     result = 0;