1 files changed, 39 insertions, 18 deletions

diff --git a/inffast.c b/inffast.c
index bbee92e..0b919bb 100644
--- a/inffast.c
+++ b/inffast.c
@@ -1,5 +1,5 @@
 /* inffast.c -- fast decoding
- * Copyright (C) 1995-2004 Mark Adler
+ * Copyright (C) 1995-2006 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -87,7 +87,7 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
     code const FAR *dcode;      /* local strm->distcode */
     unsigned lmask;             /* mask for first level of length codes */
     unsigned dmask;             /* mask for first level of distance codes */
-    code this;                  /* retrieved table entry */
+    code here;                  /* retrieved table entry */
     unsigned op;                /* code bits, operation, extra bits, or */
                                 /*  window position, window bytes to copy */
     unsigned len;               /* match length, unused bytes */
@@ -124,20 +124,20 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
             hold += (unsigned long)(PUP(in)) << bits;
             bits += 8;
         }
-        this = lcode[hold & lmask];
+        here = lcode[hold & lmask];
       dolen:
-        op = (unsigned)(this.bits);
+        op = (unsigned)(here.bits);
         hold >>= op;
         bits -= op;
-        op = (unsigned)(this.op);
+        op = (unsigned)(here.op);
         if (op == 0) {                          /* literal */
-            Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
+            Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
                     "inflate:         literal '%c'\n" :
-                    "inflate:         literal 0x%02x\n", this.val));
-            PUP(out) = (unsigned char)(this.val);
+                    "inflate:         literal 0x%02x\n", here.val));
+            PUP(out) = (unsigned char)(here.val);
         }
         else if (op & 16) {                     /* length base */
-            len = (unsigned)(this.val);
+            len = (unsigned)(here.val);
             op &= 15;                           /* number of extra bits */
             if (op) {
                 if (bits < op) {
@@ -155,14 +155,14 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
                 hold += (unsigned long)(PUP(in)) << bits;
                 bits += 8;
             }
-            this = dcode[hold & dmask];
+            here = dcode[hold & dmask];
           dodist:
-            op = (unsigned)(this.bits);
+            op = (unsigned)(here.bits);
             hold >>= op;
             bits -= op;
-            op = (unsigned)(this.op);
+            op = (unsigned)(here.op);
             if (op & 16) {                      /* distance base */
-                dist = (unsigned)(this.val);
+                dist = (unsigned)(here.val);
                 op &= 15;                       /* number of extra bits */
                 if (bits < op) {
                     hold += (unsigned long)(PUP(in)) << bits;
@@ -187,9 +187,30 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
                 if (dist > op) {                /* see if copy from window */
                     op = dist - op;             /* distance back in window */
                     if (op > whave) {
-                        strm->msg = (char *)"invalid distance too far back";
-                        state->mode = BAD;
-                        break;
+                        if (state->sane) {
+                            strm->msg = (char *)"invalid distance too far back";
+                            state->mode = BAD;
+                            break;
+                        }
+#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
+                        if (len <= op - whave) {
+                            do {
+                                PUP(out) = 0;
+                            } while (--len);
+                            continue;
+                        }
+                        len -= op - whave;
+                        do {
+                            PUP(out) = 0;
+                        } while (--op > whave);
+                        if (op == 0) {
+                            from = out - dist;
+                            do {
+                                PUP(out) = PUP(from);
+                            } while (--len);
+                            continue;
+                        }
+#endif
                     }
                     from = window - OFF;
                     if (write == 0) {           /* very common case */
@@ -259,7 +280,7 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
                 }
             }
             else if ((op & 64) == 0) {          /* 2nd level distance code */
-                this = dcode[this.val + (hold & ((1U << op) - 1))];
+                here = dcode[here.val + (hold & ((1U << op) - 1))];
                 goto dodist;
             }
             else {
@@ -269,7 +290,7 @@ unsigned start;         /* inflate()'s starting value for strm->avail_out */
             }
         }
         else if ((op & 64) == 0) {              /* 2nd level length code */
-            this = lcode[this.val + (hold & ((1U << op) - 1))];
+            here = lcode[here.val + (hold & ((1U << op) - 1))];
             goto dolen;
         }
         else if (op & 32) {                     /* end-of-block */