Carl R. Witty writes:
> In ghc 2.08 running on Linux, if you try to do an openFile for writing
> on a dangling symlink (a symlink that does not point at an existing
> file), the openFile hangs in a tight loop. strace reveals the
> following system calls:
>
> open("Parser.hs", O_WRONLY|O_NOCTTY) = -1 ENOENT (No such file or directory)
> open("Parser.hs", O_WRONLY|O_CREAT|O_EXCL|O_NOCTTY, 0666) = -1 EEXIST (File exists)
>
> repeated over and over again forever.
>
Hi,
thanks for the report - the C wrapper for openFile didn't make a
distinction between a race condition and a dangling symlink. Patch
appended.
--Sigbjorn
*** ghc/lib/cbits/openFile.lc.~3~ Sat Aug 23 13:55:54 1997
--- ghc/lib/cbits/openFile.lc Sun Nov 16 18:20:04 1997
***************
*** 67,73 ****
ghc_errtype = ERR_NOSUCHTHING;
ghc_errstr = "file does not exist";
return NULL;
! }
/* Now try to create it */
while ((fd = open(file, oflags | O_CREAT | O_EXCL, 0666)) < 0) {
if (errno == EEXIST) {
--- 67,81 ----
ghc_errtype = ERR_NOSUCHTHING;
ghc_errstr = "file does not exist";
return NULL;
! } else {
! /* If it is a dangling symlink, break off now, too. */
! struct stat st;
! if ( lstat(file,&st) == 0) {
! ghc_errtype = ERR_NOSUCHTHING;
! ghc_errstr = "dangling symlink";
! return NULL;
! }
! }
/* Now try to create it */
while ((fd = open(file, oflags | O_CREAT | O_EXCL, 0666)) < 0) {
if (errno == EEXIST) {
