[test/spec] Reproduce bugs reported by Crestwave.

Addresses issue #291.

doc/osh-manual.md

@@ -117,6 +117,15 @@ TODO: Add these
   # This relates to comments being EOL or not
 -->
 
+(7) **Ambiguous Character Classes in Globs**
+
+In short, don't use the ambiguous syntax `[[]` or `[]]` for a character class
+consisting of a single left bracket or right bracket character.
+
+Instead, use `[\[]` and `[\]]`.
+
+TODO: Explanation.
+
 ## set builtin
 
 ### errexit

native/libc_test.py

@@ -160,6 +160,12 @@ def testRegexFirstGroupMatch(self):
     self.assertRaises(
         RuntimeError, libc.regex_first_group_match, r'*', 'abcd', 0)
 
+  def testRegexFirstGroupMatchError(self):
+    # Helping to debug issue #291
+    s = ''
+    if 1:
+      libc.regex_first_group_match("(['+-'])", s, 6)
+
   def testRealpathFailOnNonexistentDirectory(self):
     # This behaviour is actually inconsistent with GNU readlink,
     # but matches behaviour of busybox readlink

spec/bugs.test.sh

@@ -17,5 +17,72 @@ a=(1 2 3)
 (( a = 42 )) 
 echo $a
 ## stdout: 42
+## N-I dash/ash stdout-json: ""
+## N-I dash/ash status: 2
+
+#### Nested % and # operators (looks like a bug, reported by Crestwave)
+var=$'\n'
+argv.py "${var#?}"
+argv.py "${var%''}"
+argv.py "${var%"${var#?}"}"
+var='a'
+argv.py "${var#?}"
+argv.py "${var%''}"
+argv.py "${var%"${var#?}"}"
+## STDOUT:
+['']
+['\n']
+['\n']
+['']
+['a']
+['a']
+## END
+## N-I dash STDOUT:
+['\\n']
+['$\\n']
+['$']
+['']
+['a']
+['a']
+## END
+
+#### # operator with single quoted arg (dash/ash and bash/mksh disagree, reported by Crestwave)
+var=a
+echo -${var#'a'}-
+echo -"${var#'a'}"-
+var="'a'"
+echo -${var#'a'}-
+echo -"${var#'a'}"-
+## STDOUT:
+--
+--
+-'a'-
+-'a'-
+## END
+## OK dash/ash STDOUT:
+--
+-a-
+-'a'-
+--
+## END
+
+#### / operator with single quoted arg (causes syntax error in regex in OSH, reported by Crestwave)
+var="++--''++--''"
+echo no plus or minus "${var//[+-]}"
+echo no plus or minus "${var//['+-']}"
+## STDOUT:
+no plus or minus ''''
+no plus or minus ''''
+## END
+## status: 0
+## OK osh STDOUT:
+no plus or minus ''''
+## END
+## OK osh status: 1
+## BUG ash STDOUT:
+no plus or minus ''''
+no plus or minus ++--++--
+## END
+## BUG ash status: 0
 ## N-I dash stdout-json: ""
 ## N-I dash status: 2

test/parse-errors.sh

@@ -368,6 +368,14 @@ args-parse-builtin() {
   # - Oil flags: invalid long flag, boolean argument, etc.
 }
 
+# aiding the transition
+args-parse-more() {
+  set +o errexit
+  _error-case 'set -z'
+  _error-case 'shopt -s foo'
+  _error-case 'shopt -z'
+}
+
 args-parse-main() {
   set +o errexit
   bin/osh --ast-format x

test/spec.sh

@@ -229,7 +229,8 @@ osh-only() {
 
 # Regress bugs
 bugs() {
-  sh-spec spec/bugs.test.sh ${REF_SHELLS[@]} $OSH_LIST "$@"
+  sh-spec spec/bugs.test.sh ${REF_SHELLS[@]} $BUSYBOX_ASH $OSH_LIST "$@" \
+    --osh-failures-allowed 2
 }
 
 blog1() {