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, 6 insertions, 6 deletions

diff --git a/tcwg-dev-build.sh b/tcwg-dev-build.sh
index 8c911c23..cf24ab60 100755
--- a/tcwg-dev-build.sh
+++ b/tcwg-dev-build.sh
@@ -6,12 +6,12 @@ scripts=$(dirname $0)
 . $scripts/jenkins-helpers.sh
 convert_args_to_variables "$@"
 
-abe_branch="${abe_branch:-tested}"
-dry_run="${dry_run:-false}"
-release_name="${release_name:-default}"
-target="${target:-aarch64-linux-gnu}"
-version="${version:-default}"
-verbose="${verbose:-true}"
+abe_branch="${abe_branch-tested}"
+dry_run="${dry_run-false}"
+release_name="${release_name-default}"
+target="${target-aarch64-linux-gnu}"
+version="${version-default}"
+verbose="${verbose-true}"
 
 set -u