bug#28002: automake prog_error when appending to configure.ac a colon-separated list of input files

[Ghulam, Sean (Nokia - FI/Espoo)]

$ automake
automake: error: src/Makefile:append/append.mk in @other_input_files
automake: @other_input_files = (src/Makefile:append/append.mk)
automake: Please contact <address@hidden>.
 at /usr/share/automake-1.13/Automake/Channels.pm line 662.
        Automake::Channels::msg('automake', '', 'src/Makefile:append/append.mk 
in @address@hidden') called at /usr/share/automake-1.13/Automake/ChannelDefs.pm 
line 212
        Automake::ChannelDefs::prog_error('src/Makefile:append/append.mk in 
@address@hidden') called at /bin/automake line 4214
        Automake::handle_configure('Makefile.am', 'Makefile.in', 'Makefile', 
'Makefile.in') called at /bin/automake line 7873
        Automake::generate_makefile('Makefile.am', 'Makefile.in') called at 
/bin/automake line 8189
        Automake::handle_makefile('Makefile.in') called at /bin/automake line 
8203
        Automake::handle_makefiles_serial() called at /bin/automake line 8337

Tested versions:  automake-1.13 and automake-1.15

How to reproduce:
Extract /usr/share/doc/automake-1.13.4/amhello-1.0.tar.gz
Create directory amhello-1.0/append
Create file amhello-1.0/append/append.mk
Add any text to amhello-1.0/append/append.mk
Edit configure.ac to include append/append.mk in AC_CONFIG_FILES as follows:

AC_CONFIG_FILES([
 Makefile
 src/Makefile:append/append.mk
])

Documentation:
AC_CONFIG_FILES 
You can override an input file name by appending to file a colon-separated list 
of
input files. Examples:
AC_CONFIG_FILES([Makefile:boiler/top.mk:boiler/bot.mk]
[lib/Makefile:boiler/lib.mk])
Doing this allows you to keep your file names acceptable to DOS variants, or to
prepend and/or append boilerplate to the file.

Best Regards,
Sean