test suite: Add bashcomp_bash env var for better control on tested bash

.travis.yml

@@ -150,6 +150,7 @@ addons:
       - yum-utils
 
 script:
+  - export bashcomp_bash=bash
   - autoreconf -i
   - ./configure
   - make -C completions check

completions/Makefile.am

@@ -946,6 +946,7 @@ install-data-local: symlinks
 check-local:
 	ret=0
 	for file in $(bashcomp_DATA) ; do \
-		$${BASH:-bash} -O extglob -n $$file || ret=$$? ; \
+		$${bashcomp_bash:-$${BASH:-bash}} \
+			-O extglob -n $$file || ret=$$? ; \
 	done ; \
 	exit $$ret

test/runCompletion

@@ -4,4 +4,5 @@
 #       isn't initialized at that point (i.e. output of `expect' is shown on
 #       stdout - `open_logs' hasn't run yet?).  And running code from a library
 #       file isn't probably a good idea either.
-exec "$BASH" "$(dirname "${BASH_SOURCE[0]}")/run" --tool completion $*
+exec "${bashcomp_bash:-$BASH}" \
+     "$(dirname "${BASH_SOURCE[0]}")/run" --tool completion $*

test/runUnit

@@ -4,4 +4,5 @@
 #       isn't initialized at that point (i.e. output of `expect' is shown on
 #       stdout - `open_logs' hasn't run yet?).  And running code from a library
 #       file isn't probably a good idea either.
-exec "$BASH" "$(dirname "${BASH_SOURCE[0]}")/run" --tool unit $*
+exec "${bashcomp_bash:-$BASH}" \
+     "$(dirname "${BASH_SOURCE[0]}")/run" --tool unit $*