[Automake-NG] [FYI] tests: we can assume GNU make: related small fixes

[Stefano Lattarini]

* t/self-check-shell-no-trail-bslash.sh: Do not explicitly
require GNU make.  Issue revealed by the maintainer check
'sc_tests_no_gmake_requirement'.
* t/ax/shell-no-trail-bslash.in: Remove workaround for BSD
make.  Improve comments.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 t/ax/shell-no-trail-bslash.in         | 11 +++++------
 t/self-check-shell-no-trail-bslash.sh |  3 ---
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/t/ax/shell-no-trail-bslash.in b/t/ax/shell-no-trail-bslash.in
index 3475398..acf833c 100644
--- a/t/ax/shell-no-trail-bslash.in
+++ b/t/ax/shell-no-trail-bslash.in
@@ -31,8 +31,9 @@ am_shell_flags=
 am_shell_command=; unset am_shell_command
 while test $# -gt 0; do
   case $1 in
-    # If the shell is invoked by make e.g. as "sh -ec" (seen on
-    # GNU make in POSIX mode) or "sh -ce" (seen on Solaris make).
+    # The shell might be invoked by make e.g. as "sh -ec" or "sh -ce".
+    # Be liberal (in the spirit of defensive programming) and accept
+    # both forms.
     -*c*)
         am_flg=$(printf '%s\n' "$1" | sed -e 's/^-//' -e 's/c//g')
         if test x"$am_flg" != x; then
@@ -49,10 +50,8 @@ while test $# -gt 0; do
 done
 
 if test x${am_shell_command+"set"} != x"set"; then
-  # Some make implementations, like *BSD's, pass the recipes to the shell
-  # through its standard input.  Trying to run our extra checks in this
-  # case would be too tricky, so we just skip them.
-  exec $am_SHELL $am_shell_flags ${1+"$@"}
+  echo "$0: fatal: no shell command given through the '-c' option" >&2
+  exit 1
 fi
 
 case $am_shell_command in
diff --git a/t/self-check-shell-no-trail-bslash.sh 
b/t/self-check-shell-no-trail-bslash.sh
index cf9c3a6..50e962f 100755
--- a/t/self-check-shell-no-trail-bslash.sh
+++ b/t/self-check-shell-no-trail-bslash.sh
@@ -17,9 +17,6 @@
 # Check that our fake "shell" used to guard against use of trailing
 # backslashes in recipes actually complains when those are used.
 
-# Our hack doesn't work with some make implementations (see comments
-# in 't/ax/shell-no-trail-bslash.in' for more details).
-required=GNUmake
 am_create_testdir=empty
 . test-init.sh
 
-- 
1.8.0.1.240.ge8a1f5a