Bug in certain use of '+=' in automake

[Andy Helten]

Hello,

The following demonstrates the problem I am seeing.  This was present in 1.4 and is still present in 1.4-p5.  The problem is a that an "extra" newline is between the initial definition of the macro and the '+=' part.

This in a Makefile.am:

blah = value1
blah += value2

Produces this in a Makefile.in:

blah = value1 value2
 

However, this in a Makefile.am:

blah = value1 \
       value2

blah += value3

Produces this in a Makefile.in:

blah = value1 value2
value3

Note there is a newline following 'value2' (in the Makefile.in) and 'value3' on a line by itself causes a Makefile error, not to mention that 'value3' is not included in the final value of 'blah'.

Andy