Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches for 2.11.0-rc2

# gpg: Signature made Fri 17 Nov 2017 17:58:36 GMT
# gpg:                using RSA key 0x7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (25 commits)
  iotests: Make 087 pass without AIO enabled
  block: Make bdrv_next() keep strong references
  qcow2: Fix overly broad madvise()
  qcow2: Refuse to get unaligned offsets from cache
  qcow2: Add bounds check to get_refblock_offset()
  block: Guard against NULL bs->drv
  qcow2: Unaligned zero cluster in handle_alloc()
  qcow2: check_errors are fatal
  qcow2: reject unaligned offsets in write compressed
  iotests: Add test for failing qemu-img commit
  tests: Add check-qobject for equality tests
  iotests: Add test for non-string option reopening
  block: qobject_is_equal() in bdrv_reopen_prepare()
  qapi: Add qobject_is_equal()
  qapi/qlist: Add qlist_append_null() macro
  qapi/qnull: Add own header
  qcow2: fix image corruption on commit with persistent bitmap
  iotests: test clearing unknown autoclear_features by qcow2
  block: Fix permissions in image activation
  qcow2: fix image corruption after committing qcow2 image into base
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/qobject/qnum.c b/qobject/qnum.c
index 476e81c93b..410686a611 100644
--- a/qobject/qnum.c
+++ b/qobject/qnum.c
@@ -213,6 +213,60 @@ QNum *qobject_to_qnum(const QObject *obj)
 }
 
 /**
+ * qnum_is_equal(): Test whether the two QNums are equal
+ *
+ * Negative integers are never considered equal to unsigned integers,
+ * but positive integers in the range [0, INT64_MAX] are considered
+ * equal independently of whether the QNum's kind is i64 or u64.
+ *
+ * Doubles are never considered equal to integers.
+ */
+bool qnum_is_equal(const QObject *x, const QObject *y)
+{
+    QNum *num_x = qobject_to_qnum(x);
+    QNum *num_y = qobject_to_qnum(y);
+
+    switch (num_x->kind) {
+    case QNUM_I64:
+        switch (num_y->kind) {
+        case QNUM_I64:
+            /* Comparison in native int64_t type */
+            return num_x->u.i64 == num_y->u.i64;
+        case QNUM_U64:
+            /* Implicit conversion of x to uin64_t, so we have to
+             * check its sign before */
+            return num_x->u.i64 >= 0 && num_x->u.i64 == num_y->u.u64;
+        case QNUM_DOUBLE:
+            return false;
+        }
+        abort();
+    case QNUM_U64:
+        switch (num_y->kind) {
+        case QNUM_I64:
+            return qnum_is_equal(y, x);
+        case QNUM_U64:
+            /* Comparison in native uint64_t type */
+            return num_x->u.u64 == num_y->u.u64;
+        case QNUM_DOUBLE:
+            return false;
+        }
+        abort();
+    case QNUM_DOUBLE:
+        switch (num_y->kind) {
+        case QNUM_I64:
+        case QNUM_U64:
+            return false;
+        case QNUM_DOUBLE:
+            /* Comparison in native double type */
+            return num_x->u.dbl == num_y->u.dbl;
+        }
+        abort();
+    }
+
+    abort();
+}
+
+/**
  * qnum_destroy_obj(): Free all memory allocated by a
  * QNum object
  */