Upgrade to pcre-3.87 (2015-04-28).

As before, dist/ is untouched upstream source.

From the release notes:

1.  When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
    for those parentheses to be closed with whatever has been captured so far.
    However, it was failing to mark any other groups between the hightest
    capture so far and the currrent group as "unset". Thus, the ovector for
    those groups contained whatever was previously there. An example is the
    pattern /(x)|((*ACCEPT))/ when matched against "abcd".

2.  If an assertion condition was quantified with a minimum of zero (an odd
    thing to do, but it happened), SIGSEGV or other misbehaviour could occur.

3.  If a pattern in pcretest input had the P (POSIX) modifier followed by an
    unrecognized modifier, a crash could occur.

4.  An attempt to do global matching in pcretest with a zero-length ovector
    caused a crash.

5.  Fixed a memory leak during matching that could occur for a subpattern
    subroutine call (recursive or otherwise) if the number of captured groups
    that had to be saved was greater than ten.

6.  Catch a bad opcode during auto-possessification after compiling a bad UTF
    string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
    UTF with NO_UTF_CHECK is documented as having an undefined outcome.

7.  A UTF pattern containing a "not" match of a non-ASCII character and a
    subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.

8. When a pattern is compiled, it remembers the highest back reference so that
   when matching, if the ovector is too small, extra memory can be obtained to
   use instead. A conditional subpattern whose condition is a check on a
   capture having happened, such as, for example in the pattern
   /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
   setting the highest backreference number. This mattered only if pcre_exec()
   was called with an ovector that was too small to hold the capture, and there
   was no other kind of back reference (a situation which is probably quite
   rare). The effect of the bug was that the condition was always treated as
   FALSE when the capture could not be consulted, leading to a incorrect
   behaviour by pcre_exec(). This bug has been fixed.

9. A reference to a duplicated named group (either a back reference or a test
   for being set in a conditional) that occurred in a part of the pattern where
   PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
   to be incorrectly calculated, leading to overwriting.

10. A mutually recursive set of back references such as (\2)(\1) caused a
    segfault at study time (while trying to find the minimum matching length).
    The infinite loop is now broken (with the minimum length unset, that is,
    zero).

11. If an assertion that was used as a condition was quantified with a minimum
    of zero, matching went wrong. In particular, if the whole group had
    unlimited repetition and could match an empty string, a segfault was
    likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
    assertions to be quantified, but not if they are being used as conditions,
    so the above pattern is faulted by Perl. PCRE has now been changed so that
    it also rejects such patterns.

12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
    failed to allow the zero-repeat case if pcre2_exec() was called with an
    ovector too small to capture the group.

13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
    Red Hat Product Security:

    (a) A crash if /K and /F were both set with the option to save the compiled
    pattern.

    (b) Another crash if the option to print captured substrings in a callout
    was combined with setting a null ovector, for example \O\C+ as a subject
    string.

14. A pattern such as "((?2){0,1999}())?", which has a group containing a
    forward reference repeated a large (but limited) number of times within a
    repeated outer group that has a zero minimum quantifier, caused incorrect
    code to be compiled, leading to the error "internal error:
    previously-checked referenced subpattern not found" when an incorrect
    memory address was read. This bug was reported as "heap overflow",
    discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
    CVE-2015-2325.

23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
    call within a group that also contained a recursive back reference caused
    incorrect code to be compiled. This bug was reported as "heap overflow",
    discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
    number CVE-2015-2326.

24. Computing the size of the JIT read-only data in advance has been a source
    of various issues, and new ones are still appear unfortunately. To fix
    existing and future issues, size computation is eliminated from the code,
    and replaced by on-demand memory allocation.

25. A pattern such as /(?i)[A-`]/, where characters in the other case are
    adjacent to the end of the range, and the range contained characters with
    more than one other case, caused incorrect behaviour when compiled in UTF
    mode. In that example, the range a-j was left out of the class.

26. Fix JIT compilation of conditional blocks, which assertion
    is converted to (*FAIL). E.g: /(?(?!))/.

27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
    discovered by the LLVM fuzzer.

28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
    when this assertion was used as a condition, for example (?(?!)a|b). In
    pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
    error about an unsupported item.

29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
    possessification code could take exponential time to complete. A recursion
    depth limit of 1000 has been imposed to limit the resources used by this
    optimization.

30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
    such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
    because \S ensures they are all in the class. The code for doing this was
    interacting badly with the code for computing the amount of space needed to
    compile the pattern, leading to a buffer overflow. This bug was discovered
    by the LLVM fuzzer.

31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
    other kinds of group caused stack overflow at compile time. This bug was
    discovered by the LLVM fuzzer.

32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
    between a subroutine call and its quantifier was incorrectly compiled,
    leading to buffer overflow or other errors. This bug was discovered by the
    LLVM fuzzer.

33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
    assertion after (?(. The code was failing to check the character after
    (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
    was discovered by the LLVM fuzzer.

34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
    a fixed maximum following a group that contains a subroutine reference was
    incorrectly compiled and could trigger buffer overflow. This bug was
    discovered by the LLVM fuzzer.

35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
    caused a stack overflow instead of the diagnosis of a non-fixed length
    lookbehind assertion. This bug was discovered by the LLVM fuzzer.

36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
    (e.g. /(?<=\Ka)/) could make pcregrep loop.

37. There was a similar problem to 36 in pcretest for global matches.

38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
    and a subsequent item in the pattern caused a non-match, backtracking over
    the repeated \X did not stop, but carried on past the start of the subject,
    causing reference to random memory and/or a segfault. There were also some
    other cases where backtracking after \C could crash. This set of bugs was
    discovered by the LLVM fuzzer.

39. The function for finding the minimum length of a matching string could take
    a very long time if mutual recursion was present many times in a pattern,
    for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
    method has been implemented. This infelicity was discovered by the LLVM
    fuzzer.

40. Static linking against the PCRE library using the pkg-config module was
    failing on missing pthread symbols.

Change-Id: Iea30c62d55ad2b5a38bbbe67e38eb5eb3952accc
diff --git a/dist/install-sh b/dist/install-sh
index 377bb86..0b0fdcb 100755
--- a/dist/install-sh
+++ b/dist/install-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2011-11-20.07; # UTC
+scriptversion=2013-12-25.23; # UTC
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -41,19 +41,15 @@
 # This script is compatible with the BSD install script, but was written
 # from scratch.
 
+tab='	'
 nl='
 '
-IFS=" ""	$nl"
+IFS=" $tab$nl"
 
-# set DOITPROG to echo to test this script
+# Set DOITPROG to "echo" to test this script.
 
-# Don't use :- since 4.3BSD and earlier shells don't like it.
 doit=${DOITPROG-}
-if test -z "$doit"; then
-  doit_exec=exec
-else
-  doit_exec=$doit
-fi
+doit_exec=${doit:-exec}
 
 # Put in absolute file names if you don't have them in your path;
 # or use environment vars.
@@ -68,17 +64,6 @@
 rmprog=${RMPROG-rm}
 stripprog=${STRIPPROG-strip}
 
-posix_glob='?'
-initialize_posix_glob='
-  test "$posix_glob" != "?" || {
-    if (set -f) 2>/dev/null; then
-      posix_glob=
-    else
-      posix_glob=:
-    fi
-  }
-'
-
 posix_mkdir=
 
 # Desired mode of installed file.
@@ -97,7 +82,7 @@
 dst_arg=
 
 copy_on_change=false
-no_target_directory=
+is_target_a_directory=possibly
 
 usage="\
 Usage: $0 [OPTION]... [-T] SRCFILE DSTFILE
@@ -137,46 +122,57 @@
     -d) dir_arg=true;;
 
     -g) chgrpcmd="$chgrpprog $2"
-	shift;;
+        shift;;
 
     --help) echo "$usage"; exit $?;;
 
     -m) mode=$2
-	case $mode in
-	  *' '* | *'	'* | *'
-'*	  | *'*'* | *'?'* | *'['*)
-	    echo "$0: invalid mode: $mode" >&2
-	    exit 1;;
-	esac
-	shift;;
+        case $mode in
+          *' '* | *"$tab"* | *"$nl"* | *'*'* | *'?'* | *'['*)
+            echo "$0: invalid mode: $mode" >&2
+            exit 1;;
+        esac
+        shift;;
 
     -o) chowncmd="$chownprog $2"
-	shift;;
+        shift;;
 
     -s) stripcmd=$stripprog;;
 
-    -t) dst_arg=$2
-	# Protect names problematic for 'test' and other utilities.
-	case $dst_arg in
-	  -* | [=\(\)!]) dst_arg=./$dst_arg;;
-	esac
-	shift;;
+    -t)
+        is_target_a_directory=always
+        dst_arg=$2
+        # Protect names problematic for 'test' and other utilities.
+        case $dst_arg in
+          -* | [=\(\)!]) dst_arg=./$dst_arg;;
+        esac
+        shift;;
 
-    -T) no_target_directory=true;;
+    -T) is_target_a_directory=never;;
 
     --version) echo "$0 $scriptversion"; exit $?;;
 
-    --)	shift
-	break;;
+    --) shift
+        break;;
 
-    -*)	echo "$0: invalid option: $1" >&2
-	exit 1;;
+    -*) echo "$0: invalid option: $1" >&2
+        exit 1;;
 
     *)  break;;
   esac
   shift
 done
 
+# We allow the use of options -d and -T together, by making -d
+# take the precedence; this is for compatibility with GNU install.
+
+if test -n "$dir_arg"; then
+  if test -n "$dst_arg"; then
+    echo "$0: target directory not allowed when installing a directory." >&2
+    exit 1
+  fi
+fi
+
 if test $# -ne 0 && test -z "$dir_arg$dst_arg"; then
   # When -d is used, all remaining arguments are directories to create.
   # When -t is used, the destination is already specified.
@@ -208,6 +204,15 @@
 fi
 
 if test -z "$dir_arg"; then
+  if test $# -gt 1 || test "$is_target_a_directory" = always; then
+    if test ! -d "$dst_arg"; then
+      echo "$0: $dst_arg: Is not a directory." >&2
+      exit 1
+    fi
+  fi
+fi
+
+if test -z "$dir_arg"; then
   do_exit='(exit $ret); exit $ret'
   trap "ret=129; $do_exit" 1
   trap "ret=130; $do_exit" 2
@@ -223,16 +228,16 @@
 
     *[0-7])
       if test -z "$stripcmd"; then
-	u_plus_rw=
+        u_plus_rw=
       else
-	u_plus_rw='% 200'
+        u_plus_rw='% 200'
       fi
       cp_umask=`expr '(' 777 - $mode % 1000 ')' $u_plus_rw`;;
     *)
       if test -z "$stripcmd"; then
-	u_plus_rw=
+        u_plus_rw=
       else
-	u_plus_rw=,u+rw
+        u_plus_rw=,u+rw
       fi
       cp_umask=$mode$u_plus_rw;;
   esac
@@ -269,41 +274,15 @@
     # If destination is a directory, append the input filename; won't work
     # if double slashes aren't ignored.
     if test -d "$dst"; then
-      if test -n "$no_target_directory"; then
-	echo "$0: $dst_arg: Is a directory" >&2
-	exit 1
+      if test "$is_target_a_directory" = never; then
+        echo "$0: $dst_arg: Is a directory" >&2
+        exit 1
       fi
       dstdir=$dst
       dst=$dstdir/`basename "$src"`
       dstdir_status=0
     else
-      # Prefer dirname, but fall back on a substitute if dirname fails.
-      dstdir=`
-	(dirname "$dst") 2>/dev/null ||
-	expr X"$dst" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
-	     X"$dst" : 'X\(//\)[^/]' \| \
-	     X"$dst" : 'X\(//\)$' \| \
-	     X"$dst" : 'X\(/\)' \| . 2>/dev/null ||
-	echo X"$dst" |
-	    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
-		   s//\1/
-		   q
-		 }
-		 /^X\(\/\/\)[^/].*/{
-		   s//\1/
-		   q
-		 }
-		 /^X\(\/\/\)$/{
-		   s//\1/
-		   q
-		 }
-		 /^X\(\/\).*/{
-		   s//\1/
-		   q
-		 }
-		 s/.*/./; q'
-      `
-
+      dstdir=`dirname "$dst"`
       test -d "$dstdir"
       dstdir_status=$?
     fi
@@ -314,74 +293,74 @@
   if test $dstdir_status != 0; then
     case $posix_mkdir in
       '')
-	# Create intermediate dirs using mode 755 as modified by the umask.
-	# This is like FreeBSD 'install' as of 1997-10-28.
-	umask=`umask`
-	case $stripcmd.$umask in
-	  # Optimize common cases.
-	  *[2367][2367]) mkdir_umask=$umask;;
-	  .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
+        # Create intermediate dirs using mode 755 as modified by the umask.
+        # This is like FreeBSD 'install' as of 1997-10-28.
+        umask=`umask`
+        case $stripcmd.$umask in
+          # Optimize common cases.
+          *[2367][2367]) mkdir_umask=$umask;;
+          .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
 
-	  *[0-7])
-	    mkdir_umask=`expr $umask + 22 \
-	      - $umask % 100 % 40 + $umask % 20 \
-	      - $umask % 10 % 4 + $umask % 2
-	    `;;
-	  *) mkdir_umask=$umask,go-w;;
-	esac
+          *[0-7])
+            mkdir_umask=`expr $umask + 22 \
+              - $umask % 100 % 40 + $umask % 20 \
+              - $umask % 10 % 4 + $umask % 2
+            `;;
+          *) mkdir_umask=$umask,go-w;;
+        esac
 
-	# With -d, create the new directory with the user-specified mode.
-	# Otherwise, rely on $mkdir_umask.
-	if test -n "$dir_arg"; then
-	  mkdir_mode=-m$mode
-	else
-	  mkdir_mode=
-	fi
+        # With -d, create the new directory with the user-specified mode.
+        # Otherwise, rely on $mkdir_umask.
+        if test -n "$dir_arg"; then
+          mkdir_mode=-m$mode
+        else
+          mkdir_mode=
+        fi
 
-	posix_mkdir=false
-	case $umask in
-	  *[123567][0-7][0-7])
-	    # POSIX mkdir -p sets u+wx bits regardless of umask, which
-	    # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
-	    ;;
-	  *)
-	    tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
-	    trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
+        posix_mkdir=false
+        case $umask in
+          *[123567][0-7][0-7])
+            # POSIX mkdir -p sets u+wx bits regardless of umask, which
+            # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
+            ;;
+          *)
+            tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
+            trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
 
-	    if (umask $mkdir_umask &&
-		exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
-	    then
-	      if test -z "$dir_arg" || {
-		   # Check for POSIX incompatibilities with -m.
-		   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
-		   # other-writable bit of parent directory when it shouldn't.
-		   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
-		   ls_ld_tmpdir=`ls -ld "$tmpdir"`
-		   case $ls_ld_tmpdir in
-		     d????-?r-*) different_mode=700;;
-		     d????-?--*) different_mode=755;;
-		     *) false;;
-		   esac &&
-		   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
-		     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
-		     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
-		   }
-		 }
-	      then posix_mkdir=:
-	      fi
-	      rmdir "$tmpdir/d" "$tmpdir"
-	    else
-	      # Remove any dirs left behind by ancient mkdir implementations.
-	      rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
-	    fi
-	    trap '' 0;;
-	esac;;
+            if (umask $mkdir_umask &&
+                exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
+            then
+              if test -z "$dir_arg" || {
+                   # Check for POSIX incompatibilities with -m.
+                   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
+                   # other-writable bit of parent directory when it shouldn't.
+                   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
+                   ls_ld_tmpdir=`ls -ld "$tmpdir"`
+                   case $ls_ld_tmpdir in
+                     d????-?r-*) different_mode=700;;
+                     d????-?--*) different_mode=755;;
+                     *) false;;
+                   esac &&
+                   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
+                     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
+                     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
+                   }
+                 }
+              then posix_mkdir=:
+              fi
+              rmdir "$tmpdir/d" "$tmpdir"
+            else
+              # Remove any dirs left behind by ancient mkdir implementations.
+              rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
+            fi
+            trap '' 0;;
+        esac;;
     esac
 
     if
       $posix_mkdir && (
-	umask $mkdir_umask &&
-	$doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
+        umask $mkdir_umask &&
+        $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
       )
     then :
     else
@@ -391,53 +370,51 @@
       # directory the slow way, step by step, checking for races as we go.
 
       case $dstdir in
-	/*) prefix='/';;
-	[-=\(\)!]*) prefix='./';;
-	*)  prefix='';;
+        /*) prefix='/';;
+        [-=\(\)!]*) prefix='./';;
+        *)  prefix='';;
       esac
 
-      eval "$initialize_posix_glob"
-
       oIFS=$IFS
       IFS=/
-      $posix_glob set -f
+      set -f
       set fnord $dstdir
       shift
-      $posix_glob set +f
+      set +f
       IFS=$oIFS
 
       prefixes=
 
       for d
       do
-	test X"$d" = X && continue
+        test X"$d" = X && continue
 
-	prefix=$prefix$d
-	if test -d "$prefix"; then
-	  prefixes=
-	else
-	  if $posix_mkdir; then
-	    (umask=$mkdir_umask &&
-	     $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
-	    # Don't fail if two instances are running concurrently.
-	    test -d "$prefix" || exit 1
-	  else
-	    case $prefix in
-	      *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
-	      *) qprefix=$prefix;;
-	    esac
-	    prefixes="$prefixes '$qprefix'"
-	  fi
-	fi
-	prefix=$prefix/
+        prefix=$prefix$d
+        if test -d "$prefix"; then
+          prefixes=
+        else
+          if $posix_mkdir; then
+            (umask=$mkdir_umask &&
+             $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
+            # Don't fail if two instances are running concurrently.
+            test -d "$prefix" || exit 1
+          else
+            case $prefix in
+              *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
+              *) qprefix=$prefix;;
+            esac
+            prefixes="$prefixes '$qprefix'"
+          fi
+        fi
+        prefix=$prefix/
       done
 
       if test -n "$prefixes"; then
-	# Don't fail if two instances are running concurrently.
-	(umask $mkdir_umask &&
-	 eval "\$doit_exec \$mkdirprog $prefixes") ||
-	  test -d "$dstdir" || exit 1
-	obsolete_mkdir_used=true
+        # Don't fail if two instances are running concurrently.
+        (umask $mkdir_umask &&
+         eval "\$doit_exec \$mkdirprog $prefixes") ||
+          test -d "$dstdir" || exit 1
+        obsolete_mkdir_used=true
       fi
     fi
   fi
@@ -472,15 +449,12 @@
 
     # If -C, don't bother to copy if it wouldn't change the file.
     if $copy_on_change &&
-       old=`LC_ALL=C ls -dlL "$dst"	2>/dev/null` &&
-       new=`LC_ALL=C ls -dlL "$dsttmp"	2>/dev/null` &&
-
-       eval "$initialize_posix_glob" &&
-       $posix_glob set -f &&
+       old=`LC_ALL=C ls -dlL "$dst"     2>/dev/null` &&
+       new=`LC_ALL=C ls -dlL "$dsttmp"  2>/dev/null` &&
+       set -f &&
        set X $old && old=:$2:$4:$5:$6 &&
        set X $new && new=:$2:$4:$5:$6 &&
-       $posix_glob set +f &&
-
+       set +f &&
        test "$old" = "$new" &&
        $cmpprog "$dst" "$dsttmp" >/dev/null 2>&1
     then
@@ -493,24 +467,24 @@
       # to itself, or perhaps because mv is so ancient that it does not
       # support -f.
       {
-	# Now remove or move aside any old file at destination location.
-	# We try this two ways since rm can't unlink itself on some
-	# systems and the destination file might be busy for other
-	# reasons.  In this case, the final cleanup might fail but the new
-	# file should still install successfully.
-	{
-	  test ! -f "$dst" ||
-	  $doit $rmcmd -f "$dst" 2>/dev/null ||
-	  { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
-	    { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
-	  } ||
-	  { echo "$0: cannot unlink or rename $dst" >&2
-	    (exit 1); exit 1
-	  }
-	} &&
+        # Now remove or move aside any old file at destination location.
+        # We try this two ways since rm can't unlink itself on some
+        # systems and the destination file might be busy for other
+        # reasons.  In this case, the final cleanup might fail but the new
+        # file should still install successfully.
+        {
+          test ! -f "$dst" ||
+          $doit $rmcmd -f "$dst" 2>/dev/null ||
+          { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
+            { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
+          } ||
+          { echo "$0: cannot unlink or rename $dst" >&2
+            (exit 1); exit 1
+          }
+        } &&
 
-	# Now rename the file to the real destination.
-	$doit $mvcmd "$dsttmp" "$dst"
+        # Now rename the file to the real destination.
+        $doit $mvcmd "$dsttmp" "$dst"
       }
     fi || exit 1