tests: make script 'shell-no-trail-bslash' simpler and more robust

This solves spurious failure in the 'check-no-trailing-backslash-in-recipes'
target for Automake-NG.

This is basically a backport of Automake-NG commit v1.14.1-1010-g85aae58;
the point is to minimize the amount of spurious diffs between the mainline
Automake and the Automake-NG source trees.

* t/ax/shell-no-trail-bslash.in: Simplify and fortify.
* t/self-check-shell-no-trail-bslash.sh: Enhance.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

1 files changed, 32 insertions, 2 deletions

diff --git a/t/self-check-shell-no-trail-bslash.sh b/t/self-check-shell-no-trail-bslash.sh
index 14ee02cdf..19198898b 100644
--- a/t/self-check-shell-no-trail-bslash.sh
+++ b/t/self-check-shell-no-trail-bslash.sh
@@ -1,5 +1,5 @@
 #! /bin/sh
-# Copyright (C) 2012-2013 Free Software Foundation, Inc.
+# Copyright (C) 2012-2014 Free Software Foundation, Inc.
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -34,12 +34,42 @@ bad:
 END
 
 SHELL=$am_testaux_builddir/shell-no-trail-bslash
+
 $SHELL -c 'exit 0'
 test "$($SHELL -c 'echo is  o\k')" = "is ok"
 
+echo 'echo is  ok\"' > ok.sh
+$SHELL ./ok.sh
+test "$($SHELL ./ok.sh)" = "is ok\""
+
+tab='	'
+nl='
+'
+for sfx in \
+  '\' \
+  '\\' \
+  '\\\\\' \
+  '\ ' \
+  "\\$tab" \
+  "\\ $tab$tab   " \
+  "\\$nl" \
+  "\\ $nl " \
+  "\\$nl$nl$nl" \
+; do
+  for pfx in "" "echo bad" ": a${nl}# multine${nl}: text"; do
+    cmd=${pfx}${sfx}
+    printf '%s\n' "$cmd" > bad.sh
+    for args in '-c "$cmd"' './bad.sh'; do
+      eval "\$SHELL $args 2>stderr && { cat stderr >&2; exit 1; }; :"
+      cat stderr >&2
+      $FGREP "recipe/script ends with backslash character" stderr
+    done
+  done
+done
+
 $MAKE good
 
 run_make -E -e FAIL bad SHELL="$SHELL"
-$FGREP "recipe ends with backslash character" stderr
+$FGREP "recipe/script ends with backslash character" stderr
 
 :