fix parsing of numbers within XML-encoded anyxml
This was caught by the libyang-cpp test suite. On Windows/MSVC, an
anyxml snippet that was parsed from this XML:
<ax xmlns="http://example.com/coze"><x>1</x><x>2</x><x>3</x></ax>
...would get printed like this:
{"example-schema:ax":{"x":["1","2","3"]}}
...while the correct form is:
{"example-schema:ax":{"x":[1,2,3]}}
This was caused by a change in `lydxml_get_hints_opaq` which probably
tried to silence a compiler warning. The code wrongly assumed that the C
`long` will be able to hold `UINT32_MAX`, which is not the case on
Windows where `long` has the same range as `int32_t`. As a result, when
the XML is parsed, these numeric values are compared against -1 on
Windows, and against 4294967295 on many other platforms, and therefore
any positive number was tagged with the hint of "this needs a 64bit
serialization" on Windows, which in turn triggers printing these values
as quoted string in JSON.
The fix simply makes sure that we never perform a narrowing conversion
from a constant. I was looking for a way of using explicitly sized types
(i.e., int64_t in this case), but there's only `strtoll` in C. The
alternative would be `sscanf(... SCNd64 ...)`, but the semantics is
subtly different when it comes to whitespace.
The bisecting process was non-trivial for me because the workflow which
bypasses CI introduced a test regression (fixed by commit 7ebd607ee,
"test UPDATE message changed") and a temporary Windows breakage (fixed
by commit a1ecc1695, "compat BUGFIX regression in win timegm support").
Instead of a simple `git bisect`, this required some manual patch
backporting.
Fixes: 21eaa39f9 libyang BUGFIX type size problems
diff --git a/src/parser_xml.c b/src/parser_xml.c
index 0db10ca..944d3d5 100644
--- a/src/parser_xml.c
+++ b/src/parser_xml.c
@@ -441,7 +441,9 @@
{
struct lyd_node_opaq *opaq;
char *ptr;
- long num;
+ /* this needs to be at least 64bit, and it "should not" be an explicit int64_t
+ * because the code calls strtoll later on, which "might" return a bigger type */
+ long long num;
*hints = 0;
*anchor = NULL;
@@ -453,11 +455,11 @@
/* boolean value */
*hints |= LYD_VALHINT_BOOLEAN;
} else {
- num = strtol(value, &ptr, 10);
+ num = strtoll(value, &ptr, 10);
if ((unsigned)(ptr - value) == value_len) {
/* number value */
*hints |= LYD_VALHINT_DECNUM;
- if ((num < INT32_MIN) || (num > (long)UINT32_MAX)) {
+ if ((num < INT32_MIN) || (num > UINT32_MAX)) {
/* large number */
*hints |= LYD_VALHINT_NUM64;
}