Test that a default written out loads in every position, null outside a column is refused, an alternation reads a field once, and the CLI's lone reference refuses an empty segment

name_test.go

@@ -192,6 +192,12 @@ func TestNameErrors(t *testing.T) {
 			`no field "zz"`},
 		{"read by nothing", map[string]string{"word": `["a","b"]`, "card": `"{/word as w}"`},
 			`nothing reads name "w"`},
+		{"one arm read twice in an alternation", map[string]string{"cat": `{"format":"{w|w}","w":["a","b"]}`, "card": `"{/cat as n}{n} {n.w}"`},
+			""},
+		{"a field and a path into it in one alternation", map[string]string{"cat": `{"format":"{w|w.x}","w":{"format":"{x}","x":["a","b"]}}`, "card": `"{/cat as n}{n} {n.w}"`},
+			""},
+		{"one field read in two alternations", map[string]string{"cat": `{"format":"{w|v}{w|v}","w":["a","b"],"v":["c","d"]}`, "card": `"{/cat as n}{n} {n.w}"`},
+			`renders field "w" twice`},
 		{"read in a repeat", map[string]string{"nm.json": `{"format":"{first}","rows":"nm.tsv"}`, "nm.tsv": "first\tlast\nAda\tByron\nBo\tEk\n", "person": `{"format":"{first} {last}","first":"{/nm.first}","last":"{/nm.last}"}`, "card": `{"format":"{/person as p}{each}","each":{"format":"{p.first}","repeat":2}}`},
 			""},
 		{"a misspelt name", map[string]string{"word": `["a","b"]`, "card": `"{/word as p}{p}{p}{pp}"`},