LYNX-DEV ^Z patch for 2.7.1

[John E. Davis]

From the PROBLEMS file:

    Control-Z on Unix can cause aberrant behavior.  If you encounter

I think this is due to not handling the select system call properly.
If ^Z is pressed while select is being called, after resumption,
select will return -1 with errno set to EINTR.  This situation does
not appear to be handled properly.  Below I have attached a patch to
lynx2-7-1/WWW/Library/Implementation/HTTCP.c that should fix this.

I patched the file in two places.  Basically the trick is to replace:

     timeout.tv_sec = 0;
     timeout.tv_usec = 100000;
     FD_ZERO(&readfds);
     FD_SET(fildes, &readfds);
     ret = select(FD_SETSIZE, (void *)&readfds, NULL, NULL, &timeout);
     if (ret == -1)
       return -1;                      /* failed */

with:

  do
    {
       timeout.tv_sec = 0;
       timeout.tv_usec = 100000;
       FD_ZERO(&readfds);
       FD_SET(fildes, &readfds);
       ret = select(FD_SETSIZE, (void *)&readfds, NULL, NULL, &timeout);
    }
  while ((ret == -1)
         && (errno == EINTR));

  if (ret == -1)
    return -1;                 /* failed */


Here is the complete patch:

    
--- HTTCP.c.orig        Wed Feb 26 12:44:28 1997
+++ HTTCP.c     Mon May 12 19:15:24 1997
@@ -769,6 +769,13 @@
            else
 #endif /* SOCKS */
             ret = select(FD_SETSIZE, NULL, (void *)&writefds, NULL, &timeout);
+
+          /* If we suspend, then it is possible that select will be 
+           * interrupted.  Allow for this possibility.
+           */
+          if ((ret == -1) && (errno == EINTR))
+            continue;
+
             /*
             **  Again according to the Sun and Motorola man pagse for connect:
             **     EALREADY            The socket is non-blocking and a  previ-
@@ -923,16 +930,22 @@
            return HT_INTERRUPTED;
        }
 
-        timeout.tv_sec = 0;
-       timeout.tv_usec = 100000;
-        FD_ZERO(&readfds);
-        FD_SET(fildes, &readfds);
+       do
+        {
+           timeout.tv_sec = 0;
+           timeout.tv_usec = 100000;
+           FD_ZERO(&readfds);
+           FD_SET(fildes, &readfds);
 #ifdef SOCKS
-       if (socks_flag)
-            ret = Rselect(FD_SETSIZE, (void *)&readfds, NULL, NULL, &timeout);
-       else
+           if (socks_flag)
+             ret = Rselect(FD_SETSIZE, (void *)&readfds, NULL, NULL, &timeout);
+           else
 #endif /* SOCKS */
-        ret = select(FD_SETSIZE, (void *)&readfds, NULL, NULL, &timeout);
+             ret = select(FD_SETSIZE, (void *)&readfds, NULL, NULL, &timeout);
+        }
+       while ((ret == -1)
+             && (errno == EINTR));
+       
         if (ret < 0) {
             return -1;
         } else if (ret > 0) {

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