bpo-32255: Always quote a single empty field when write into a CSV file. (#4769)

This allows to distinguish an empty row from a row consisting of a single empty field.
diff --git a/Misc/ACKS b/Misc/ACKS
index 54d8d62..8303ce8 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1554,6 +1554,7 @@
 Arfrever Frehtes Taifersar Arahesis
 Hideaki Takahashi
 Takase Arihiro
+Licht Takeuchi
 Indra Talip
 Neil Tallim
 Geoff Talvola
diff --git a/Misc/NEWS.d/next/Library/2017-12-12-07-29-06.bpo-32255.2bfNmM.rst b/Misc/NEWS.d/next/Library/2017-12-12-07-29-06.bpo-32255.2bfNmM.rst
new file mode 100644
index 0000000..dafee67
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2017-12-12-07-29-06.bpo-32255.2bfNmM.rst
@@ -0,0 +1,3 @@
+A single empty field is now always quoted when written into a CSV file.
+This allows to distinguish an empty row from a row consisting of a single empty field.
+Patch by Licht Takeuchi.