expand,interp: adapt to Bash 5.0 changes

The order in which associative array keys and values are printed has
changed. Before it was sorting by key; now it appears to sort in an
arbitrary way, such as via the hash table.

'man bash' still doesn't document what the order is, so let's keep the
simple order and have the tests sort manually.

'${!a}' now errors if the variable is empty, so do that too.

Updates mvdan#346.

expand/param.go

@@ -106,7 +106,9 @@ func (cfg *Config) paramExp(pe *syntax.ParamExp) (string, error) {
 			for k := range vr.Map {
 				strs = append(strs, k)
 			}
-		} else if str != "" {
+		} else if !syntax.ValidName(str) {
+			return "", fmt.Errorf("invalid indirect expansion")
+		} else {
 			vr = cfg.Env.Get(str)
 			strs = append(strs, vr.String())
 		}
@@ -315,15 +317,11 @@ func (cfg *Config) varInd(vr Variable, idx syntax.ArithmExpr) (string, error) {
 	case Associative:
 		switch lit := nodeLit(idx); lit {
 		case "@", "*":
-			var strs []string
-			keys := make([]string, 0, len(vr.Map))
-			for k := range vr.Map {
-				keys = append(keys, k)
-			}
-			sort.Strings(keys)
-			for _, k := range keys {
-				strs = append(strs, vr.Map[k])
+			strs := make([]string, 0, len(vr.Map))
+			for _, val := range vr.Map {
+				strs = append(strs, val)
 			}
+			sort.Strings(strs)
 			if lit == "*" {
 				return cfg.ifsJoin(strs), nil
 			}

interp/interp.go

@@ -116,15 +116,10 @@ func (r *Runner) updateExpandOpts() {
 }
 
 func (r *Runner) expandErr(err error) {
-	switch err := err.(type) {
-	case nil:
-	case expand.UnsetParameterError:
-		r.errf("%s\n", err.Message)
+	if err != nil {
+		r.errf("%v\n", err)
 		r.exit = 1
 		r.setErr(ShellExitStatus(r.exit))
-	default:
-		r.setErr(err)
-		r.exit = 1
 	}
 }
 

interp/interp_test.go

@@ -288,8 +288,12 @@ var fileCases = []struct {
 	{"a=(a bcd); echo ${#a} ${#a[@]} ${#a[*]} ${#a[1]}", "1 2 2 3\n"},
 	{"set -- a bc; echo ${#@} ${#*} $#", "2 2 2\n"},
 	{
-		"echo ${!a}; a=b; echo ${!a}; b=c; echo ${!a}",
-		"\n\nc\n",
+		"echo ${!a}; echo more",
+		"invalid indirect expansion\nexit status 1 #JUSTERR",
+	},
+	{
+		"a=b; echo ${!a}; b=c; echo ${!a}",
+		"\nc\n",
 	},
 	{
 		"a=foo; echo ${a:1}; echo ${a: -1}; echo ${a: -10}; echo ${a:5}",
@@ -1834,20 +1838,20 @@ set +o pipefail
 		"\n\nb\n\n",
 	},
 	{
-		`declare -A a=([x]=b [y]=c); echo ${a[@]}; echo ${a[*]}`,
-		"b c\nb c\n",
+		`declare -A a=([x]=b [y]=c); for e in ${a[@]}; do echo $e; done | sort`,
+		"b\nc\n",
 	},
 	{
-		`declare -A a=([y]=b [x]=c); echo ${a[@]}; echo ${a[*]}`,
-		"c b\nc b\n",
+		`declare -A a=([y]=b [x]=c); for e in ${a[*]}; do echo $e; done | sort`,
+		"b\nc\n",
 	},
 	{
-		`declare -A a=([x]=a); a["y"]=d; a["x"]=c; echo ${a[@]}`,
-		"c d\n",
+		`declare -A a=([x]=a); a["y"]=d; a["x"]=c; for e in ${a[@]}; do echo $e; done | sort`,
+		"c\nd\n",
 	},
 	{
-		`declare -A a=([x]=a); a[y]=d; a[x]=c; echo ${a[@]}`,
-		"c d\n",
+		`declare -A a=([x]=a); a[y]=d; a[x]=c; for e in ${a[@]}; do echo $e; done | sort`,
+		"c\nd\n",
 	},
 	{
 		// cheating a little; bash just did a=c
@@ -1866,10 +1870,10 @@ set +o pipefail
 	// weird assignments
 	{"a=b; a=(c d); echo ${a[@]}", "c d\n"},
 	{"a=(b c); a=d; echo ${a[@]}", "d c\n"},
-	{"declare -A a=([x]=b [y]=c); a=d; echo ${a[@]}", "d b c\n"},
+	{"declare -A a=([x]=b [y]=c); a=d; for e in ${a[@]}; do echo $e; done | sort", "b\nc\nd\n"},
 	{"i=3; a=b; a[i]=x; echo ${a[@]}", "b x\n"},
 	{"i=3; declare a=(b); a[i]=x; echo ${!a[@]}", "0 3\n"},
-	{"i=3; declare -A a=(['x']=b); a[i]=x; echo ${!a[@]}", "i x\n"},
+	{"i=3; declare -A a=(['x']=b); a[i]=x; for e in ${!a[@]}; do echo $e; done | sort", "i\nx\n"},
 
 	// declare
 	{"declare -B foo", "declare: invalid option \"-B\"\nexit status 2 #JUSTERR"},

interp/module_test.go

@@ -71,7 +71,7 @@ var modCases = []struct {
 			return fmt.Errorf("blacklisted: %s", args[0])
 		},
 		src:  "a=$(malicious)",
-		want: "blacklisted: malicious",
+		want: "blacklisted: malicious\nexit status 1",
 	},
 	{
 		name: "ExecBackground",