1 files changed, 14 insertions, 2 deletions
diff --git a/libgo/go/encoding/csv/writer.go b/libgo/go/encoding/csv/writer.go
index 1faecb66480..17e7bb7f5c7 100644
--- a/libgo/go/encoding/csv/writer.go
+++ b/libgo/go/encoding/csv/writer.go
@@ -115,10 +115,22 @@ func (w *Writer) WriteAll(records [][]string) (err error) {
 }
 
 // fieldNeedsQuotes returns true if our field must be enclosed in quotes.
-// Empty fields, files with a Comma, fields with a quote or newline, and
+// Fields with a Comma, fields with a quote or newline, and
 // fields which start with a space must be enclosed in quotes.
+// We used to quote empty strings, but we do not anymore (as of Go 1.4).
+// The two representations should be equivalent, but Postgres distinguishes
+// quoted vs non-quoted empty string during database imports, and it has
+// an option to force the quoted behavior for non-quoted CSV but it has
+// no option to force the non-quoted behavior for quoted CSV, making
+// CSV with quoted empty strings strictly less useful.
+// Not quoting the empty string also makes this package match the behavior
+// of Microsoft Excel and Google Drive.
+// For Postgres, quote the data termating string `\.`.
 func (w *Writer) fieldNeedsQuotes(field string) bool {
-	if len(field) == 0 || strings.IndexRune(field, w.Comma) >= 0 || strings.IndexAny(field, "\"\r\n") >= 0 {
+	if field == "" {
+		return false
+	}
+	if field == `\.` || strings.IndexRune(field, w.Comma) >= 0 || strings.IndexAny(field, "\"\r\n") >= 0 {
 		return true
 	}