shell: some additions to *sh-misc/* tests

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/ash_test/ash-misc/assignment2.right

@@ -0,0 +1,2 @@
+./assignment2.tests: line 2: a=b: not found
+127

shell/ash_test/ash-misc/assignment2.tests

@@ -0,0 +1,3 @@
+# This must not be interpreted as an assignment
+a''=b true
+echo $?

shell/ash_test/ash-misc/empty_args.right

@@ -0,0 +1,6 @@
+Null 0th arg:
+./empty_args.tests: line 2: : Permission denied
+127
+Null 1st arg:
+0
+Null arg in exec:

shell/ash_test/ash-misc/empty_args.tests

@@ -0,0 +1,9 @@
+echo Null 0th arg:
+""
+echo $?
+echo Null 1st arg:
+# printf without args would print usage info
+printf ""
+echo $?
+echo Null arg in exec:
+exec printf ""

shell/ash_test/ash-misc/env_and_func.right

@@ -0,0 +1,2 @@
+var=val
+var=val

shell/ash_test/ash-misc/env_and_func.tests

@@ -0,0 +1,8 @@
+var=old
+f() { echo "var=$var"; }
+# bash: POSIXLY_CORRECT behavior is to "leak" new variable values
+# out of function invocations (similar to "special builtins" behavior);
+# but in "bash mode", they don't leak.
+# hush does not "leak" values. ash does.
+var=val f
+echo "var=$var"

shell/hush_test/hush-misc/env_and_func.tests

@@ -1,4 +1,8 @@
 var=old
 f() { echo "var=$var"; }
+# bash: POSIXLY_CORRECT behavior is to "leak" new variable values
+# out of function invocations (similar to "special builtins" behavior);
+# but in "bash mode", they don't leak.
+# hush does not "leak" values. ash does.
 var=val f
 echo "var=$var"