Merge #10019: Fix regression relative to 2.6: add newlines if indent=0
Patch by Amaury Forgeot d'Arc, updated by Sando Tosi.
diff --git a/Doc/library/json.rst b/Doc/library/json.rst
index 6bb7fe3..9064409 100644
--- a/Doc/library/json.rst
+++ b/Doc/library/json.rst
@@ -136,10 +136,10 @@
If *indent* is a non-negative integer or string, then JSON array elements and
object members will be pretty-printed with that indent level. An indent level
- of 0 or ``""`` will only insert newlines. ``None`` (the default) selects the
- most compact representation. Using an integer indent indents that many spaces
- per level. If *indent* is a string (such at '\t'), that string is used to indent
- each level.
+ of 0, negative, or ``""`` will only insert newlines. ``None`` (the default)
+ selects the most compact representation. Using a positive integer indent
+ indents that many spaces per level. If *indent* is a string (such at '\t'),
+ that string is used to indent each level.
If *separators* is an ``(item_separator, dict_separator)`` tuple, then it
will be used instead of the default ``(', ', ': ')`` separators. ``(',',