queue: fix QTAILQ_FOREACH_REVERSE_SAFE

The iteration was stopping as soon as prev_var was set to NULL, and
therefore it skipped the first element.  Fortunately, or unfortunately,
we have only one use of QTAILQ_FOREACH_REVERSE_SAFE.  Thus this only
showed up as incorrect register preferences on the very first translation
block that was compiled.

Reported-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/qemu/queue.h b/include/qemu/queue.h
index 1f8e219412739f3ccb3228f4b36aecb2dcf72b7c..0379bd8fdbb074682094ad432b840626a17d1353 100644 (file)
--- a/include/qemu/queue.h
+++ b/include/qemu/queue.h
@@ -439,7 +439,7 @@ union {                                                                 \
 
 #define QTAILQ_FOREACH_REVERSE_SAFE(var, head, field, prev_var)         \
         for ((var) = QTAILQ_LAST(head);                                 \
-             (var) && ((prev_var) = QTAILQ_PREV(var, field));           \
+             (var) && ((prev_var) = QTAILQ_PREV(var, field), 1);        \
              (var) = (prev_var))
 
 /*