[Emacs-diffs] /srv/bzr/emacs/trunk r111804: Don't set h_errno on MS-Windows except in gethostbyname.

[Eli Zaretskii]

------------------------------------------------------------
revno: 111804
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Sat 2013-02-16 13:08:49 +0200
message:
  Don't set h_errno on MS-Windows except in gethostbyname.
  
  See http://lists.gnu.org/archive/html/emacs-devel/2013-02/msg00293.html
  and the following discussion for the details.
  
   src/w32.c (set_errno): Reset h_errno and don't set it to any other
   value.  Set errno instead.
   (check_errno): Reset h_errno.
   (sys_socket, socket_to_fd, sys_bind, sys_connect)
   (sys_gethostname, sys_getservbyname, sys_getpeername)
   (sys_shutdown, sys_setsockopt, sys_listen, sys_getsockname)
   (sys_accept, sys_recvfrom, sys_sendto, fcntl, sys_read): Don't set
   h_errno.
   (sys_gethostbyname): Set h_errno only errors detected.
modified:
  src/ChangeLog
  src/w32.c

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2013-02-15 19:37:29 +0000
+++ b/src/ChangeLog     2013-02-16 11:08:49 +0000
@@ -1,3 +1,15 @@
+2013-02-16  Eli Zaretskii  <address@hidden>
+
+       * w32.c (set_errno): Reset h_errno and don't set it to any other
+       value.  Set errno instead.
+       (check_errno): Reset h_errno.
+       (sys_socket, socket_to_fd, sys_bind, sys_connect)
+       (sys_gethostname, sys_getservbyname, sys_getpeername)
+       (sys_shutdown, sys_setsockopt, sys_listen, sys_getsockname)
+       (sys_accept, sys_recvfrom, sys_sendto, fcntl, sys_read): Don't set
+       h_errno.
+       (sys_gethostbyname): Set h_errno only errors detected.
+
 2013-02-15  Paul Eggert  <address@hidden>
 
        * process.c (h_errno) [!HAVE_H_ERRNO]: Remove unused decl.

=== modified file 'src/w32.c'
--- a/src/w32.c 2013-02-15 17:31:12 +0000
+++ b/src/w32.c 2013-02-16 11:08:49 +0000
@@ -6092,35 +6092,39 @@
 
 int h_errno = 0;
 
-/* function to set h_errno for compatibility; map winsock error codes to
-   normal system codes where they overlap (non-overlapping definitions
-   are already in <sys/socket.h> */
+/* Function to map winsock error codes to errno codes for those errno
+   code defined in errno.h (errno values not defined by errno.h are
+   already in nt/inc/sys/socket.h).  */
 static void
 set_errno (void)
 {
+  int wsa_err;
+
+  h_errno = 0;
   if (winsock_lib == NULL)
-    h_errno = EINVAL;
+    wsa_err = EINVAL;
   else
-    h_errno = pfn_WSAGetLastError ();
+    wsa_err = pfn_WSAGetLastError ();
 
-  switch (h_errno)
+  switch (wsa_err)
     {
-    case WSAEACCES:            h_errno = EACCES; break;
-    case WSAEBADF:             h_errno = EBADF; break;
-    case WSAEFAULT:            h_errno = EFAULT; break;
-    case WSAEINTR:             h_errno = EINTR; break;
-    case WSAEINVAL:            h_errno = EINVAL; break;
-    case WSAEMFILE:            h_errno = EMFILE; break;
-    case WSAENAMETOOLONG:      h_errno = ENAMETOOLONG; break;
-    case WSAENOTEMPTY:         h_errno = ENOTEMPTY; break;
+    case WSAEACCES:            errno = EACCES; break;
+    case WSAEBADF:             errno = EBADF; break;
+    case WSAEFAULT:            errno = EFAULT; break;
+    case WSAEINTR:             errno = EINTR; break;
+    case WSAEINVAL:            errno = EINVAL; break;
+    case WSAEMFILE:            errno = EMFILE; break;
+    case WSAENAMETOOLONG:      errno = ENAMETOOLONG; break;
+    case WSAENOTEMPTY:         errno = ENOTEMPTY; break;
+    default:                   errno = wsa_err; break;
     }
-  errno = h_errno;
 }
 
 static void
 check_errno (void)
 {
-  if (h_errno == 0 && winsock_lib != NULL)
+  h_errno = 0;
+  if (winsock_lib != NULL)
     pfn_WSASetLastError (0);
 }
 
@@ -6232,7 +6236,7 @@
 
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return INVALID_SOCKET;
     }
 
@@ -6242,13 +6246,7 @@
   s = pfn_socket (af, type, protocol);
 
   if (s != INVALID_SOCKET)
-    {
-      int retval = socket_to_fd (s);
-
-      if (retval == -1)
-       errno = h_errno;
-      return retval;
-    }
+    return socket_to_fd (s);
 
   set_errno ();
   return -1;
@@ -6344,8 +6342,9 @@
       /* clean up */
       _close (fd);
     }
+  else
   pfn_closesocket (s);
-  h_errno = EMFILE;
+  errno = EMFILE;
   return -1;
 }
 
@@ -6354,7 +6353,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENOTSOCK;
+      errno = ENOTSOCK;
       return SOCKET_ERROR;
     }
 
@@ -6366,7 +6365,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6375,7 +6374,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENOTSOCK;
+      errno = ENOTSOCK;
       return SOCKET_ERROR;
     }
 
@@ -6387,7 +6386,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6416,12 +6415,20 @@
 sys_gethostname (char * name, int namelen)
 {
   if (winsock_lib != NULL)
-    return pfn_gethostname (name, namelen);
+    {
+      int retval;
+
+      check_errno ();
+      retval = pfn_gethostname (name, namelen);
+      if (retval == SOCKET_ERROR)
+       set_errno ();
+      return retval;
+    }
 
   if (namelen > MAX_COMPUTERNAME_LENGTH)
     return !GetComputerName (name, (DWORD *)&namelen);
 
-  errno = h_errno = EFAULT;
+  errno = EFAULT;
   return SOCKET_ERROR;
 }
 
@@ -6429,17 +6436,24 @@
 sys_gethostbyname (const char * name)
 {
   struct hostent * host;
+  int h_err = h_errno;
 
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      h_errno = NO_RECOVERY;
+      errno = ENETDOWN;
       return NULL;
     }
 
   check_errno ();
   host = pfn_gethostbyname (name);
   if (!host)
-    set_errno ();
+    {
+      set_errno ();
+      h_errno = errno;
+    }
+  else
+    h_errno = h_err;
   return host;
 }
 
@@ -6450,7 +6464,7 @@
 
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return NULL;
     }
 
@@ -6466,7 +6480,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6478,7 +6492,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6487,7 +6501,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6499,7 +6513,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6508,7 +6522,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6521,7 +6535,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6530,7 +6544,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6544,7 +6558,7 @@
        fd_info[s].flags |= FILE_LISTEN;
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6553,7 +6567,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6565,7 +6579,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6574,7 +6588,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return -1;
     }
 
@@ -6586,11 +6600,7 @@
       if (t == INVALID_SOCKET)
        set_errno ();
       else
-       {
-         fd = socket_to_fd (t);
-         if (fd < 0)
-           errno = h_errno;    /* socket_to_fd sets h_errno */
-       }
+       fd = socket_to_fd (t);
 
       if (fd >= 0)
        {
@@ -6599,7 +6609,7 @@
        }
       return fd;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return -1;
 }
 
@@ -6609,7 +6619,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6621,7 +6631,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6631,7 +6641,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return SOCKET_ERROR;
     }
 
@@ -6643,7 +6653,7 @@
        set_errno ();
       return rc;
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -6654,7 +6664,7 @@
 {
   if (winsock_lib == NULL)
     {
-      errno = h_errno = ENETDOWN;
+      errno = ENETDOWN;
       return -1;
     }
 
@@ -6673,11 +6683,11 @@
        }
       else
        {
-         h_errno = EINVAL;
+         errno = EINVAL;
          return SOCKET_ERROR;
        }
     }
-  errno = h_errno = ENOTSOCK;
+  errno = ENOTSOCK;
   return SOCKET_ERROR;
 }
 
@@ -7108,7 +7118,7 @@
              pfn_ioctlsocket (SOCK_HANDLE (fd), FIONREAD, &waiting);
              if (waiting == 0 && nchars == 0)
                {
-                 h_errno = errno = EWOULDBLOCK;
+                 errno = EWOULDBLOCK;
                  return -1;
                }