sync with source (for race condition fix attempt)

git-svn-id: svn://tug.org/texlive/trunk@42426 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 18 insertions, 3 deletions

diff --git a/Master/texmf-dist/web2c/mktexdir b/Master/texmf-dist/web2c/mktexdir
index f39408b4c1f..86d34f81df7 100755
--- a/Master/texmf-dist/web2c/mktexdir
+++ b/Master/texmf-dist/web2c/mktexdir
@@ -1,12 +1,13 @@
 #!/bin/sh
-# mkinstalldirs (now mktexdir) -- make directory hierarchy.
+# mktexdir (was mkinstalldirs) -- make directory hierarchy.
 # Author: Noah Friedman <friedman@prep.ai.mit.edu>, created: 1993-05-16.
 # Public domain.
 # 
 # Modified for sticky directory creation, --help, --version, more,
 # by Thomas Esser, Karl Berry, Olaf Weber, et al.
+# Maintained as part of TeX Live, http://tug.org/tex-live.
 
-version='$Id: mktexdir 34656 2014-07-18 23:38:50Z karl $'
+version='$Id: mktexdir 42425 2016-11-02 21:34:11Z karl $'
 progname=`echo $0 | sed 's%.*/%%'`
 
 # preferentially use subprograms from our own directory.
@@ -50,7 +51,18 @@ do
      pathcomp="$pathcomp$d"
 
      if test ! -d "./$pathcomp"; then
-        mkdir "./$pathcomp" || { errstatus=$?; break; }
+        # This shell stuff is not atomic, therefore ./$pathcomp
+        # may have been created in another process and this mkdir will
+        # fail despite the above test, so do it silently:
+        mkdir "./$pathcomp" >/dev/null 2>&1
+        
+        # So, if ./$pathcomp is a directory now, call it good.
+        if test ! -d "./$pathcomp"; then
+          # Otherwise, presumably it's a real error.  Do the mkdir again
+          # and let the error be seen, and quit the loop.
+          # (Report at https://bugs.debian.org/794228.)
+          mkdir "./$pathcomp" || { errstatus=$?; break; }
+        fi
         chmod `kpsestat ${MT_APPEND_MASK} "$pathcomp"/..` "./$pathcomp"
      fi
 
@@ -59,3 +71,6 @@ do
 done
 
 exit $errstatus
+
+# P.S. We don't want to rely on mkdir -p, because of possible
+# portability programs. See current mkinstalldirs source (in Automake).