'compile' script calls mv in a way that fails

[Bruno Haible]

Hi,

When automake's 'compile' script is called for files in the current directory,
it invokes 'mv' in a way that fails.

Using automake 1.11 and autoconf 2.64.

How to reproduce:

Check out a recent gnulib.
$ ./gnulib-tool --create-testdir --dir=$HOME/data/tmp/testdir3 mbscasestr
$ cd /tmp
$ cat > oldcc <<\EOF
#!/bin/sh
case " $* " in
  *" -c "*)
    case " $* " in
      *" -o "*)
        echo "oldcc: -o and -c incompatible" 1>&2
        exit 1
        ;;
    esac
    ;;
esac
exec gcc "$@"
EOF
$ chmod a+x oldcc
$ cd /tmp/testdir3
$ ./configure CC=/tmp/oldcc
$ make
...
make[4]: Entering directory `/tmp/testdir3/gllib'
source='localcharset.c' object='localcharset.o' libtool=no \
        DEPDIR=.deps depmode=none /bin/sh ../build-aux/depcomp \
        /tmp/testdir3/build-aux/compile /tmp/oldcc -DHAVE_CONFIG_H -I. -I..     
-g -O2 -c -o localcharset.o localcharset.c
mv: `localcharset.o' and `localcharset.o' are the same file

When GNU mv produces this error message, it also errs out with exit code 1.
Here is a proposed patch (tested):


2009-10-03  Bruno Haible  <address@hidden>

        * lib/compile: Don't attempt to move the generated file to its target
        destination when it is already at the target destination. Avoids an mv
        failure.

*** automake/lib/compile.bak    2009-10-03 14:26:24.000000000 +0200
--- automake/lib/compile        2009-10-03 14:29:07.000000000 +0200
***************
*** 123,132 ****
  "$@"
  ret=$?
  
! if test -f "$cofile"; then
!   mv "$cofile" "$ofile"
! elif test -f "${cofile}bj"; then
!   mv "${cofile}bj" "$ofile"
  fi
  
  rmdir "$lockdir"
--- 123,134 ----
  "$@"
  ret=$?
  
! if test "$ofile" != "$cofile"; then
!   if test -f "$cofile"; then
!     mv "$cofile" "$ofile"
!   elif test -f "${cofile}bj"; then
!     mv "${cofile}bj" "$ofile"
!   fi
  fi
  
  rmdir "$lockdir"