fix the case with maxolen == 0 in compress

diff --git a/modules/deflate.c b/modules/deflate.c
index 67c6c16b71ea35dd6cc918693f2f3ab95237b59d..bf1d318e5c805cc8c4ad96eab62241b370b0187f 100644 (file)
--- a/modules/deflate.c
+++ b/modules/deflate.c
@@ -27,7 +27,7 @@
  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  * OR MODIFICATIONS.
  *
  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  * OR MODIFICATIONS.
  *

- * $Id: deflate.c,v 1.6 1997/11/27 06:05:17 paulus Exp $
+ * $Id: deflate.c,v 1.7 1997/11/27 06:25:19 paulus Exp $

  */
 
 #ifdef AIX4
  */
 
 #ifdef AIX4


@@ -286,8 +286,15 @@ z_compress(arg, mret, mp, orig_len, maxolen)
     /* Allocate one mblk initially. */
     if (maxolen > orig_len)
        maxolen = orig_len;
     /* Allocate one mblk initially. */
     if (maxolen > orig_len)
        maxolen = orig_len;

-    wspace = maxolen < 4096? maxolen: 4096;
-    m = allocb(wspace, BPRI_MED);
+    if (maxolen <= PPP_HDRLEN + 2) {
+       wspace = 0;
+       m = NULL;
+    } else {
+       wspace = maxolen + state->hdrlen;
+       if (wspace > 4096)
+           wspace = 4096;
+       m = allocb(wspace, BPRI_MED);
+    }

     if (m != NULL) {
        *mret = m;
        if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {
     if (m != NULL) {
        *mret = m;
        if (state->hdrlen + PPP_HDRLEN + 2 < wspace) {


@@ -343,11 +350,16 @@ z_compress(arg, mret, mp, orig_len, maxolen)
                m->b_wptr += wspace;
                olen += wspace;
                wspace = maxolen - olen;
                m->b_wptr += wspace;
                olen += wspace;
                wspace = maxolen - olen;

-               if (wspace < 32)
-                   wspace = 32;
-               else if (wspace > 4096)
-                   wspace = 4096;
-               m->b_cont = allocb(wspace, BPRI_MED);
+               if (wspace <= 0) {
+                   wspace = 0;
+                   m->b_cont = NULL;
+               } else {
+                   if (wspace < 32)
+                       wspace = 32;
+                   else if (wspace > 4096)
+                       wspace = 4096;
+                   m->b_cont = allocb(wspace, BPRI_MED);
+               }

                m = m->b_cont;
                if (m != NULL) {
                    state->strm.next_out = m->b_wptr;
                m = m->b_cont;
                if (m != NULL) {
                    state->strm.next_out = m->b_wptr;


@@ -360,8 +372,10 @@ z_compress(arg, mret, mp, orig_len, maxolen)
            }
        }
     }
            }
        }
     }

-    m->b_wptr += wspace - state->strm.avail_out;
-    olen += wspace - state->strm.avail_out;
+    if (m != NULL) {
+       m->b_wptr += wspace - state->strm.avail_out;
+       olen += wspace - state->strm.avail_out;
+    }

 
     /*
      * See if we managed to reduce the size of the packet.
 
     /*
      * See if we managed to reduce the size of the packet.