[PATCH 2/4] {minor} install-sh: assume ${var:-value} works as expected

The Autoconf manual says it is OK these days.

* lib/install.sh: Adjust.
* NEWS: Update.

Signed-off-by: Stefano Lattarini <[email protected]>
---
 NEWS           | 6 ++++--
 lib/install-sh | 9 ++-------
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/NEWS b/NEWS
index 50f1e7f..37f513b 100644
--- a/NEWS
+++ b/NEWS
@@ -108,8 +108,10 @@ New in 1.15:
 
 * Cleanups and modernizations:
 
-  - The install-sh script now unconditionally assumes that a working
-    'dirname' program is available.
+  - The install-sh script has been modernized, and now makes the following
+    assumptions unconditionally:
+    (1) a working 'dirname' program is available;
+    (2) the ${var:-value} shell parameters substitution works;
 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/lib/install-sh b/lib/install-sh
index f950f30..9a7bad8 100755
--- a/lib/install-sh
+++ b/lib/install-sh
@@ -45,15 +45,10 @@ nl='
 '
 IFS=" ""	$nl"
 
-# set DOITPROG to echo to test this script
+# Set DOITPROG to "echo" to test this script.
 
-# Don't use :- since 4.3BSD and earlier shells don't like it.
 doit=${DOITPROG-}
-if test -z "$doit"; then
-  doit_exec=exec
-else
-  doit_exec=$doit
-fi
+doit_exec=${doit:-exec}
 
 # Put in absolute file names if you don't have them in your path;
 # or use environment vars.
-- 
1.8.3.1.605.g85318f5