ui/table: fix width calculation of multi-line column headers

internal/ui/table/table.go

@@ -142,7 +142,7 @@ func (t *Table) Write(w io.Writer) error {
 	for i, desc := range t.columns {
 		for _, line := range strings.Split(desc, "\n") {
 			if columnWidths[i] < ui.TerminalDisplayWidth(line) {
-				columnWidths[i] = ui.TerminalDisplayWidth(desc)
+				columnWidths[i] = ui.TerminalDisplayWidth(line)
 			}
 		}
 	}

internal/ui/table/table_test.go

@@ -29,6 +29,21 @@ first column
 ----------------------
 data: first data field
 ----------------------
+`,
+		},
+		{
+			func(t testing.TB) *Table {
+				table := New()
+				table.AddColumn("first\ncolumn", "{{.First}}")
+				table.AddRow(struct{ First string }{"data"})
+				return table
+			},
+			`
+first
+column
+------
+data
+------
 `,
 		},
 		{