bug#17354: distclean fails when source is relatively otherplace

[Jan Engelhardt]

With automake-1.13.4 & automake-1.14, when there is a _SOURCES = 
../blah.c, make does not properly run because .deps is gone too early.


File set:

# Makefile.am
SUBDIRS = b
noinst_PROGRAMS = foo

# configure.ac
AC_INIT([a],[0])
AM_INIT_AUTOMAKE([foreign subdir-objects])
AC_PROG_CC
AC_CONFIG_FILES([Makefile b/Makefile])
AC_OUTPUT

# foo.c
int main(void){return 0;}

# b/Makefile.am
noinst_PROGRAMS = bar
bar_SOURCES = ../foo.c


Observed:

01:43 wrgstfl:/dev/shm/testcase > make distclean
Making distclean in b
make[1]: Entering directory `/dev/shm/testcase/b'
test -z "bar" || rm -f bar
rm -f *.o
rm -f ../*.o
rm -f *.tab.c
test -z "" || rm -f 
test . = "." || test -z "" || rm -f 
rm -f ../.deps/.dirstamp
rm -f ../.dirstamp
rm -f TAGS ID GTAGS GRTAGS GSYMS GPATH tags
rm -rf ../.deps
rm -f Makefile
make[1]: Leaving directory `/dev/shm/testcase/b'
make[1]: Entering directory `/dev/shm/testcase'
Makefile:348: .deps/foo.Po: No such file or directory
make[1]: *** No rule to make target `.deps/foo.Po'.  Stop.
make[1]: Leaving directory `/dev/shm/testcase'
make: *** [distclean-recursive] Error 1


Expected:

Don't fail.


Additional information:

The problem is also observable without using "..";
foo_SOURCES = b/foo.c, bar_SOURCES = foo.c
also yields the same issue that one .deps is gone before the Makefile of 
another directory is executed.