[PATCH v2 17/19] cutils: Use parse_uint in qemu_strtosz for negative rejection

[Eric Blake <eblake@redhat.com>]

Rather than open-coding two different ways to check for an unwanted
negative sign, reuse the same code in both functions.  That way, if we
decide down the road to accept "-0" instead of rejecting it, we have
fewer places to change.  Also, it means we now get ERANGE instead of
EINVAL for negative values in qemu_strtosz, which is reasonable for
what it represents.

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 tests/unit/test-cutils.c | 7 +++----
 util/cutils.c            | 8 ++------
 2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/tests/unit/test-cutils.c b/tests/unit/test-cutils.c
index 1272638582a..b8ad4d7fbac 100644
--- a/tests/unit/test-cutils.c
+++ b/tests/unit/test-cutils.c
@@ -3396,10 +3396,9 @@ static void test_qemu_strtosz_trailing(void)
 static void test_qemu_strtosz_erange(void)
 {
     /* FIXME negative values fit better as ERANGE */
-    do_strtosz(" -0", -EINVAL /* FIXME -ERANGE */, 0, 0 /* FIXME 3 */);
-    do_strtosz("-1", -EINVAL /* FIXME -ERANGE */, 0, 0 /* FIXME 2 */);
-    do_strtosz_full("-2M", qemu_strtosz, -EINVAL /* FIXME -ERANGE */, 0,
-                    0 /* FIXME 2 */, -EINVAL, 0);
+    do_strtosz(" -0", -ERANGE, 0, 3);
+    do_strtosz("-1", -ERANGE, 0, 2);
+    do_strtosz_full("-2M", qemu_strtosz, -ERANGE, 0, 2, -EINVAL, 0);
     do_strtosz(" -.0", -EINVAL /* FIXME -ERANGE */, 0, 0 /* FIXME 4 */);
     do_strtosz_full("-.1k", qemu_strtosz, -EINVAL /* FIXME -ERANGE */, 0,
                     0 /* FIXME 3 */, -EINVAL, 0);
diff --git a/util/cutils.c b/util/cutils.c
index b5a6641fa0f..550abbe5c06 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -201,6 +201,7 @@ static int64_t suffix_mul(char suffix, int64_t unit)
  * - hex with scaling suffix, such as 0x20M
  * - octal, such as 08
  * - fractional hex, such as 0x1.8
+ * - negative values, including -0
  * - floating point exponents, such as 1e3
  *
  * The end pointer will be returned in *end, if not NULL.  If there is
@@ -226,15 +227,10 @@ static int do_strtosz(const char *nptr, const char **end,
     int64_t mul;

     /* Parse integral portion as decimal. */
-    retval = qemu_strtou64(nptr, &endptr, 10, &val);
+    retval = parse_uint(nptr, &endptr, 10, &val);
     if (retval) {
         goto out;
     }
-    if (memchr(nptr, '-', endptr - nptr) != NULL) {
-        endptr = nptr;
-        retval = -EINVAL;
-        goto out;
-    }
     if (val == 0 && (*endptr == 'x' || *endptr == 'X')) {
         /* Input looks like hex; reparse, and insist on no fraction or suffix. */
         retval = qemu_strtou64(nptr, &endptr, 16, &val);
-- 
2.40.1