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, 13 insertions, 13 deletions

diff --git a/tcwg_kernel-build.sh b/tcwg_kernel-build.sh
index f9ba98b0..c67b7ca4 100755
--- a/tcwg_kernel-build.sh
+++ b/tcwg_kernel-build.sh
@@ -12,7 +12,7 @@ declare -A git_branch
 convert_args_to_variables "@@gnu-default" "@@llvm-default" "@@linux-default" "$@"
 
 # Execution mode: baseline, jenkins-full, bisect.
-mode="${mode:-baseline}"
+mode="${mode-baseline}"
 
 # Toolchain to use: gnu or llvm
 obligatory_variables toolchain
@@ -25,18 +25,18 @@ esac
 
 # Set custom revision for one of the projects, and use baseline revisions
 # for all other projects.
-current_project="${current_project:-none}"
-current_rev="${current_rev:-default}"
-
-linux_config="${linux_config:-defconfig}"
-reset_baseline="${reset_baseline:-false}"
-start_at="${start_at:-default}"
-finish_at="${finish_at:-default}"
-target="${target:-native}"
-tidy="${tidy:-true}"
-top_artifacts="${top_artifacts:-$(pwd)/artifacts}"
-verbose="${verbose:-true}"
-verbose2="${verbose2:-false}"
+current_project="${current_project-none}"
+current_rev="${current_rev-default}"
+
+linux_config="${linux_config-defconfig}"
+reset_baseline="${reset_baseline-false}"
+start_at="${start_at-default}"
+finish_at="${finish_at-default}"
+target="${target-native}"
+tidy="${tidy-true}"
+top_artifacts="${top_artifacts-$(pwd)/artifacts}"
+verbose="${verbose-true}"
+verbose2="${verbose2-false}"
 
 set -u