Recent versions of gcc have introduced compiler warnings for string
operations that could be truncated. This caused problems with -Werror.
src/error.c used strncpy to write "..." to a string, but skipped writing
the NUL terminator. Switch this to use memcpy. src/load.c produced
warnings from snprintf writing error strings that could be truncated.
Added code to autotools build to detect `-Wno-format-truncation', add it
to AM_CFLAGS if supported.
This adds a compiler warning when strbuffer_init return value is
ignored. unpack_object is updated to deal with errors produced
while building unrecognized_keys.
This macro is used to conditionally generate GCC/CLANG __attribute__
declarations if supported.
This allows the compiler to produce warnings on certain incorrect
usages. json_sprintf and json_vsprintf will produce warnings on invalid
format string. Many functions will produce a warning if the result is
unused. Specifically functions which allocate new objects will warn if
the result is ignored as this always results in a memory leak.
* Test equality of different length strings.
* Add tab to json_pack whitespace test.
* Test json_sprintf with empty result and invalid UTF.
* Test json_get_alloc_funcs with NULL arguments.
* Test invalid arguments.
* Add test_chaos to test allocation failure code paths.
* Remove redundant json_is_string checks from json_string_equal and
json_string_copy. Both functions are static and can only be called
with a json string.
Fixes to issues found by test_chaos:
* Fix crash on OOM in pack_unpack.c:read_string().
* Unconditionally free string in string_create upon allocation failure.
Update load.c:parse_value() to reflect this. This resolves a leak on
allocation failure for pack_unpack.c:pack_string() and
value.c:json_sprintf().
Although not visible from CodeCoverage these changes significantly
increase branch coverage. Especially in src/value.c where we previously
covered 67.4% of branches and now cover 96.3% of branches.
The `O` format causes reference counts to increase, but in an error they
are not released. Callers to unpack functions that use the `O` format
should use pointers pre-initialized to NULL so they can safely release
the reference on error.
Also corrected typo which said this was like `O` (itself).
Fixes#135
