It's now an error to try to add an object or array to itself. The
encoder checks for circular references and fails with an error status
if one is detected.
Some day we will have ANSI C compatibility... This change doesn't make
the API backwards incompatible because uint32_t was only used in flags
to json_dump*() and the flags are meant to be used only by ORing
constants and macro output, and actually currently only JSON_INDENT
can be used.
Don't alloca() a whitespace buffer and fill it with spaces in each
call to dump_indent. Instead, use a static whitespace buffer.
As a bonus, this saves the use of poorly portable alloca().
Inside strings, All UTF-8 characters except for \, " and Unicode
control codes are dumped as-is. The control codes that have a special
one-character escape use that escape, and other control codes are
dumped using the \uXXXX escape.
Nothing was appended to strbuffer, so the buffer was left empty. An
empty strbuffer is not an empty string but NULL, so the result was a
segfault.
This patch fixes the problem by initializing strbuffer to an empty
string.
String buffer (strbuffer) is an object that resizes automatically when
data is added to it. It was implemented by generalizing the technique
used in json_dumps().
