compress: guard against NULL compress in get_error/close

Return a static message from compress_get_error() and no-op in
compress_close() when compress is NULL.

Link: https://lore.kernel.org/alsa-devel/CAOH03+3bBSMrvVdxH5qQB8nvnejJAtnS3gnH4b5mO2fPugeZuw@mail.gmail.com/
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/src/lib/compress.c b/src/lib/compress.c
index c0b547bb978ec45791d023f38ad47fde5a2ffc8b..c2859e1911c02a77c03d4bfb4b5554154779e50b 100644 (file)
--- a/src/lib/compress.c
+++ b/src/lib/compress.c
@@ -78,6 +78,8 @@ extern struct compress_ops compress_hw_ops;
 
 const char *compress_get_error(struct compress *compress)
 {
+       if (!compress)
+               return "compress device not opened";
        return compress->ops->get_error(compress->data);
 }
 
@@ -193,6 +195,8 @@ struct compress *compress_open_by_name(const char *name,
 
 void compress_close(struct compress *compress)
 {
+       if (!compress)
+               return;
        compress->ops->close(compress->data);
        if (compress->dl_hdl)
                dlclose(compress->dl_hdl);