Make makelock and readlock work on filesystems without symlink support.

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Make makelock and readlock work on filesystems without symlink support.
This way you can have a repository on a fat partiton, e.g. a USB stick.

manifest hash: cea2c120ef2b25a50c5d98b59648f773feefe470
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mercurial/lock.py

@@ -1,49 +1,49 b''
 # lock.py - simple locking scheme for mercurial
 #
 # Copyright 2005 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 import os, time
 import util
 
 class LockHeld(Exception):
     pass
 
 class lock:
     def __init__(self, file, wait = 1):
         self.f = file
         self.held = 0
         self.wait = wait
         self.lock()
 
     def __del__(self):
         self.release()
 
     def lock(self):
         while 1:
             try:
                 self.trylock()
                 return 1
             except LockHeld, inst:
                 if self.wait:
                     time.sleep(1)
                     continue
                 raise inst
 
     def trylock(self):
         pid = os.getpid()
         try:
             util.makelock(str(pid), self.f)
             self.held = 1
-        except:
+        except (OSError, IOError):
             raise LockHeld(util.readlock(self.f))
 
     def release(self):
         if self.held:
             self.held = 0
             try:
                 os.unlink(self.f)
             except: pass
 

mercurial/util.py

@@ -1,111 +1,126 b''
 # util.py - utility functions and platform specfic implementations
 #
 # Copyright 2005 K. Thananchayan <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
-import os
+import os, errno
 
 def unique(g):
     seen = {}
     for f in g:
         if f not in seen:
             seen[f] = 1
             yield f
 
 class CommandError(Exception): pass
 
 def explain_exit(code):
     """return a 2-tuple (desc, code) describing a process's status"""
     if os.WIFEXITED(code):
         val = os.WEXITSTATUS(code)
         return "exited with status %d" % val, val
     elif os.WIFSIGNALED(code):
         val = os.WTERMSIG(code)
         return "killed by signal %d" % val, val
     elif os.WIFSTOPPED(code):
         val = os.WSTOPSIG(code)
         return "stopped by signal %d" % val, val
     raise ValueError("invalid exit code")
 
 def system(cmd, errprefix=None):
     """execute a shell command that must succeed"""
     rc = os.system(cmd)
     if rc:
         errmsg = "%s %s" % (os.path.basename(cmd.split(None, 1)[0]),
                             explain_exit(rc)[0])
         if errprefix:
             errmsg = "%s: %s" % (errprefix, errmsg)
         raise CommandError(errmsg)
 
 def rename(src, dst):
     try:
         os.rename(src, dst)
     except:
         os.unlink(dst)
         os.rename(src, dst)
 
 def copytree(src, dst, copyfile):
     """Copy a directory tree, files are copied using 'copyfile'."""
     names = os.listdir(src)
     os.mkdir(dst)
 
     for name in names:
         srcname = os.path.join(src, name)
         dstname = os.path.join(dst, name)
         if os.path.isdir(srcname):
             copytree(srcname, dstname, copyfile)
         elif os.path.isfile(srcname):
             copyfile(srcname, dstname)
         else:
             raise IOError("Not a regular file: %r" % srcname)
 
+def _makelock_file(info, pathname):
+    ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
+    os.write(ld, info)
+    os.close(ld)
+
+def _readlock_file(pathname):
+    return file(pathname).read()
+
 # Platfor specific varients
 if os.name == 'nt':
     nulldev = 'NUL:'
 
     def is_exec(f, last):
         return last
 
     def set_exec(f, mode):
         pass
 
     def pconvert(path):
         return path.replace("\\", "/")
 
-    def makelock(info, pathname):
-        ld = os.open(pathname, os.O_CREAT | os.O_WRONLY | os.O_EXCL)
-        os.write(ld, info)
-        os.close(ld)
-
-    def readlock(pathname):
-        return file(pathname).read()
+    makelock = _makelock_file
+    readlock = _readlock_file
 
 else:
     nulldev = '/dev/null'
 
     def is_exec(f, last):
         return (os.stat(f).st_mode & 0100 != 0)
 
     def set_exec(f, mode):
         s = os.stat(f).st_mode
         if (s & 0100 != 0) == mode:
             return
         if mode:
             # Turn on +x for every +r bit when making a file executable
             # and obey umask.
             umask = os.umask(0)
             os.umask(umask)
             os.chmod(f, s | (s & 0444) >> 2 & ~umask)
         else:
             os.chmod(f, s & 0666)
 
     def pconvert(path):
         return path
 
     def makelock(info, pathname):
-        os.symlink(info, pathname)
+        try:
+            os.symlink(info, pathname)
+        except OSError, why:
+            if why.errno == errno.EEXIST:
+                raise
+            else:
+                _makelock_file(info, pathname)
 
     def readlock(pathname):
-        return os.readlink(pathname)
+        try:
+            return os.readlink(pathname)
+        except OSError, why:
+            if why.errno == errno.EINVAL:
+                return _readlock_file(pathname)
+            else:
+                raise