[nasm:nasm-2.15.xx] preproc: correctly handle %00 capturing a label

[nasm-bot for H. Peter Anvin (Intel)]

Commit-ID:  23abe9fe88a0d045e063627e682a540a5d06779c
Gitweb:     http://repo.or.cz/w/nasm.git?a=commitdiff;h=23abe9fe88a0d045e063627e682a540a5d06779c
Author:     H. Peter Anvin (Intel) <hpa at zytor.com>
AuthorDate: Fri, 10 Jul 2020 01:52:49 -0700
Committer:  H. Peter Anvin (Intel) <hpa at zytor.com>
CommitDate: Fri, 10 Jul 2020 01:52:49 -0700

preproc: correctly handle %00 capturing a label

defining->dstk.mmac should point back to "defining" when the topmost
definition block is a %macro block.

Otherwise %00 will not inhibit label emission.

Signed-off-by: H. Peter Anvin (Intel) <hpa at zytor.com>


---
 asm/preproc.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/asm/preproc.c b/asm/preproc.c
index 81c72042..4fcdb359 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -4035,7 +4035,13 @@ issue_error:
         nasm_assert(!defining);
         nasm_new(def);
         def->casesense = casesense;
-        def->dstk.mmac = defining;
+        /*
+         * dstk.mstk points to the previous definition bracket,
+         * whereas dstk.mmac points to the topmost mmacro, which
+         * in this case is the one we are just starting to create.
+         */
+        def->dstk.mstk = defining;
+        def->dstk.mmac = def;
         if (op == PP_RMACRO)
             def->max_depth = nasm_limit[LIMIT_MACRO_LEVELS];
         if (!parse_mmacro_spec(tline, def, dname)) {