Z_PARTIAL_FLUSH is marked deprecated. Z_SYNC_FLUSH is the suggested

replacement but only use it for inflate. For deflate use Z_FINISH
as Z_SYNC_FLUSH adds a trailing marker in some cases that inflate(),
despite the comment in zlib, does npt seem to cope well with, resulting
in errors when uncompressing exactly fills the outbut buffer without
a Z_STREAM_END and a successive call returns an error.

MFC after:	6 days

1 files changed, 10 insertions, 6 deletions

diff --git a/sys/opencrypto/deflate.c b/sys/opencrypto/deflate.c
index 239435e..852b66a 100644
--- a/sys/opencrypto/deflate.c
+++ b/sys/opencrypto/deflate.c
@@ -138,8 +138,8 @@ deflate_global(data, size, decomp, out)
 		goto bad;
 	}
 	for (;;) {
-		error = decomp ? inflate(&zbuf, Z_PARTIAL_FLUSH) :
-				 deflate(&zbuf, Z_PARTIAL_FLUSH);
+		error = decomp ? inflate(&zbuf, Z_SYNC_FLUSH) :
+				 deflate(&zbuf, Z_FINISH);
 		if (error != Z_OK && error != Z_STREAM_END) {
 			/*
 			 * Unfortunately we are limited to 5 arguments,
@@ -153,9 +153,13 @@ deflate_global(data, size, decomp, out)
 			    zbuf.state->dummy, zbuf.total_out);
 			goto bad;
 		}
-		else if (zbuf.avail_in == 0 && zbuf.avail_out != 0)
-			goto end;
-		else if (zbuf.avail_out == 0 && i < (ZBUF - 1)) {
+		if (decomp && zbuf.avail_in == 0 && error == Z_STREAM_END) {
+			/* Done. */
+			break;
+		} else if (!decomp && error == Z_STREAM_END) {
+			/* Done. */
+			break;
+		} else if (zbuf.avail_out == 0) {
 			/* we need more output space, allocate size */
 			buf[i].out = malloc((u_long) size,
 			    M_CRYPTO_DATA, M_NOWAIT);
@@ -170,6 +174,7 @@ deflate_global(data, size, decomp, out)
 			zbuf.avail_out = buf[i].size;
 			i++;
 		} else {
+			/* Unexpect result. */
 			/*
 			 * Unfortunately we are limited to 5 arguments,
 			 * thus, again, use two probes.
@@ -184,7 +189,6 @@ deflate_global(data, size, decomp, out)
 		}
 	}
 
-end:
 	result = count = zbuf.total_out;
 
 	*out = malloc((u_long) result, M_CRYPTO_DATA, M_NOWAIT);