commit 426a60efaf6a2fa0183875d2f31aefe98575306f
author Petteri Aimonen <jpa@git.mail.kapsi.fi> Fri Nov 26 20:09:41 2021 +0200
committer Petteri Aimonen <jpa@git.mail.kapsi.fi> Fri Nov 26 20:12:18 2021 +0200
tree 83e0f8d8acaa9a5ee2901208f8631780155444bf
parent ab19ecbe1b9f377ab4ee8e762bfe16c39068ad68

Fix compiler warning with PB_BUFFER_ONLY (#717)

I also took the opportunity to get rid of a potential undefined behavior.
Now the marker value used is a valid const int pointer.

pb_encode.c

diff --git a/pb_encode.c b/pb_encode.c
index f5f1676..2ad9925 100644
--- a/pb_encode.c
+++ b/pb_encode.c
@@ -65,7 +65,11 @@
 {
     pb_ostream_t stream;
 #ifdef PB_BUFFER_ONLY
-    stream.callback = (void*)1; /* Just a marker value */
+    /* In PB_BUFFER_ONLY configuration the callback pointer is just int*.
+     * NULL pointer marks a sizing field, so put a non-NULL value to mark a buffer stream.
+     */
+    static const int marker;
+    stream.callback = ▮
 #else
     stream.callback = &buf_write;
 #endif

pb_encode.h

diff --git a/pb_encode.h b/pb_encode.h
index 9cff22a..8913683 100644
--- a/pb_encode.h
+++ b/pb_encode.h
@@ -33,7 +33,7 @@
      * Also, NULL pointer marks a 'sizing stream' that does not
      * write anything.
      */
-    int *callback;
+    const int *callback;
 #else
     bool (*callback)(pb_ostream_t *stream, const pb_byte_t *buf, size_t count);
 #endif