Don't ignore "null" values in variable expansions

Replace ${var:-default} with ${var-default}.

I learned something new about shell scripting today.  From bash manual:
===
When not performing substring expansion, using the form described
below (e.g., ‘:-’), Bash tests for a parameter that is unset or null.
Omitting the colon results in a test only for a parameter that is
unset. Put another way, if the colon is included, the operator tests
for both parameter’s existence and that its value is not null; if
the colon is omitted, the operator tests only for existence.
===

The immediate problem I need to fix is handling of
host_aarchXX_excludecheck and host_x86_64_excludecheck parameters
in tcwg-buildfarm.sh.  With ":-" syntax the empty ("null") values are
replaced by defaults, causing GCC testsuite to be ignored on aarchXX
hosts when "--host_aarchXX_excludecheck ''" is given.

There happens to be a single usage ":-" in ${rw:-rw} in
start-container-qemu.sh, where ":-" is actually needed.

Change-Id: Ibc8e070b698e1c76e2161eb65d40639b8cdec1f3

1 files changed, 1 insertions, 1 deletions

diff --git a/TestRelease.job b/TestRelease.job
index e7db8878..afc004ae 100755
--- a/TestRelease.job
+++ b/TestRelease.job
@@ -92,7 +92,7 @@ fi
 
 # Compile the test case
 rm -f ${testdir}/hi
-params="-o ${testdir}/hi ${testdir}/hello.cpp ${specs:-} -static"
+params="-o ${testdir}/hi ${testdir}/hello.cpp ${specs-} -static"
 if test ${win32} -eq 0; then
     ${testdir}/${dir}/bin/${target}-c++ ${params}
 else