X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=inftrees.c;h=09462a740b12c1c2aba231d01ccff91e1db7ae0d;hb=HEAD;hp=b8a2aa4c2bc45270fc3004cfd1c52dbec308f585;hpb=df60b50769ae9441c6ebd853948ee7da559286e0;p=zlib.git

diff --git a/inftrees.c b/inftrees.c
index b8a2aa4..09462a7 100644
--- a/inftrees.c
+++ b/inftrees.c
@@ -1,5 +1,5 @@
 /* inftrees.c -- generate Huffman trees for efficient decoding
- * Copyright (C) 1995-2011 Mark Adler
+ * Copyright (C) 1995-2022 Mark Adler
  * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
@@ -9,7 +9,7 @@
 #define MAXBITS 15
 
 const char inflate_copyright[] =
-   " inflate 1.2.5.3 Copyright 1995-2011 Mark Adler ";
+   " inflate 1.2.12 Copyright 1995-2022 Mark Adler ";
 /*
   If you use the zlib library in a product, an acknowledgment is welcome
   in the documentation of your product. If for some reason you cannot
@@ -54,7 +54,7 @@ unsigned short FAR *work;
     code FAR *next;             /* next available space in table */
     const unsigned short FAR *base;     /* base value table to use */
     const unsigned short FAR *extra;    /* extra bits table to use */
-    int end;                    /* use base and extra for symbol > end */
+    unsigned match;             /* use base and extra for symbol >= match */
     unsigned short count[MAXBITS+1];    /* number of codes of each length */
     unsigned short offs[MAXBITS+1];     /* offsets in table for each length */
     static const unsigned short lbase[31] = { /* Length codes 257..285 base */
@@ -62,7 +62,7 @@ unsigned short FAR *work;
         35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
     static const unsigned short lext[31] = { /* Length codes 257..285 extra */
         16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18,
-        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 71, 64};
+        19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21, 16, 199, 202};
     static const unsigned short dbase[32] = { /* Distance codes 0..29 base */
         1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
         257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
@@ -181,19 +181,17 @@ unsigned short FAR *work;
     switch (type) {
     case CODES:
         base = extra = work;    /* dummy value--not used */
-        end = 19;
+        match = 20;
         break;
     case LENS:
         base = lbase;
-        base -= 257;
         extra = lext;
-        extra -= 257;
-        end = 256;
+        match = 257;
         break;
-    default:            /* DISTS */
+    default:    /* DISTS */
         base = dbase;
         extra = dext;
-        end = -1;
+        match = 0;
     }
 
     /* initialize state for loop */
@@ -208,21 +206,21 @@ unsigned short FAR *work;
     mask = used - 1;            /* mask for comparing low */
 
     /* check available table space */
-    if ((type == LENS && used >= ENOUGH_LENS) ||
-        (type == DISTS && used >= ENOUGH_DISTS))
+    if ((type == LENS && used > ENOUGH_LENS) ||
+        (type == DISTS && used > ENOUGH_DISTS))
         return 1;
 
     /* process all codes and make table entries */
     for (;;) {
         /* create table entry */
         here.bits = (unsigned char)(len - drop);
-        if ((int)(work[sym]) < end) {
+        if (work[sym] + 1U < match) {
             here.op = (unsigned char)0;
             here.val = work[sym];
         }
-        else if ((int)(work[sym]) > end) {
-            here.op = (unsigned char)(extra[work[sym]]);
-            here.val = base[work[sym]];
+        else if (work[sym] >= match) {
+            here.op = (unsigned char)(extra[work[sym] - match]);
+            here.val = base[work[sym] - match];
         }
         else {
             here.op = (unsigned char)(32 + 64);         /* end of block */
@@ -277,8 +275,8 @@ unsigned short FAR *work;
 
             /* check for enough space */
             used += 1U << curr;
-            if ((type == LENS && used >= ENOUGH_LENS) ||
-                (type == DISTS && used >= ENOUGH_DISTS))
+            if ((type == LENS && used > ENOUGH_LENS) ||
+                (type == DISTS && used > ENOUGH_DISTS))
                 return 1;
 
             /* point entry in root table to sub-table */