Make compression functions return void.

The return value wasn't used to indicate failure; it only indicated
whether any compression was being done at all or whether the
compression method was ssh_comp_none, and we can tell the latter just
as well by the fact that its init function returns a null context
pointer.

ssh.c

@@ -341,7 +341,11 @@ static void *ssh_comp_none_init(void)
 static void ssh_comp_none_cleanup(void *handle)
 {
 }
-static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
+static void ssh_comp_none_block(void *handle, unsigned char *block, int len,
+                                unsigned char **outblock, int *outlen)
+{
+}
+static int ssh_decomp_none_block(void *handle, unsigned char *block, int len,
                                  unsigned char **outblock, int *outlen)
 {
     return 0;
@@ -353,7 +357,7 @@ static int ssh_comp_none_disable(void *handle)
 const static struct ssh_compress ssh_comp_none = {
     "none", NULL,
     ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
-    ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
+    ssh_comp_none_init, ssh_comp_none_cleanup, ssh_decomp_none_block,
     ssh_comp_none_disable, NULL
 };
 extern const struct ssh_compress ssh_zlib;

ssh.h

@@ -560,7 +560,7 @@ struct ssh_compress {
     const char *delayed_name;
     void *(*compress_init) (void);
     void (*compress_cleanup) (void *);
-    int (*compress) (void *, unsigned char *block, int len,
+    void (*compress) (void *, unsigned char *block, int len,
                       unsigned char **outblock, int *outlen);
     void *(*decompress_init) (void);
     void (*decompress_cleanup) (void *);
@@ -981,7 +981,7 @@ void *zlib_compress_init(void);
 void zlib_compress_cleanup(void *);
 void *zlib_decompress_init(void);
 void zlib_decompress_cleanup(void *);
-int zlib_compress_block(void *, unsigned char *block, int len,
+void zlib_compress_block(void *, unsigned char *block, int len,
                          unsigned char **outblock, int *outlen);
 int zlib_decompress_block(void *, unsigned char *block, int len,
 			  unsigned char **outblock, int *outlen);

ssh2bpp.c

@@ -537,20 +537,18 @@ static void ssh2_bpp_format_packet(BinaryPacketProtocol *bpp, PktOut *pkt)
                    pkt->downstream_id, pkt->additional_log_text);
     }
 
+    if (s->out.comp && s->out.comp_ctx) {
+        unsigned char *newpayload;
+        int newlen;
         /*
          * Compress packet payload.
          */
-    {
+        s->out.comp->compress(s->out.comp_ctx, pkt->data + 5, pkt->length - 5,
-        unsigned char *newpayload;
+                              &newpayload, &newlen);
-        int newlen;
-        if (s->out.comp && s->out.comp->compress(
-                s->out.comp_ctx, pkt->data + 5, pkt->length - 5,
-                &newpayload, &newlen)) {
         pkt->length = 5;
         put_data(pkt, newpayload, newlen);
         sfree(newpayload);
     }
-    }
 
     /*
      * Add padding. At least four bytes, and must also bring total

sshzlib.c

@@ -679,7 +679,7 @@ static int zlib_disable_compression(void *handle)
     return n;
 }
 
-int zlib_compress_block(void *handle, unsigned char *block, int len,
+void zlib_compress_block(void *handle, unsigned char *block, int len,
                          unsigned char **outblock, int *outlen)
 {
     struct LZ77Context *ectx = (struct LZ77Context *)handle;
@@ -796,8 +796,6 @@ int zlib_compress_block(void *handle, unsigned char *block, int len,
 
     *outblock = out->outbuf;
     *outlen = out->outlen;
-
-    return 1;
 }
 
 /* ----------------------------------------------------------------------