Make sure that the hash-table index can't overflow its variable.

diff --git a/dynamic_hash.diff b/dynamic_hash.diff
index 2a6026f..cd002e9 100644 (file)
--- a/dynamic_hash.diff
+++ b/dynamic_hash.diff
@@ -19,7 +19,7 @@ An extended version of a patch by Shachar Shemesh.
  static int false_alarms;
  static int tag_hits;
  static int matches;
-@@ -42,47 +37,36 @@ static int total_matches;
+@@ -42,47 +37,37 @@ static int total_matches;
  
  extern struct stats stats;
  
@@ -39,7 +39,7 @@ An extended version of a patch by Shachar Shemesh.
 -{
 -      return (int)t1->t - (int)t2->t;
 -}
-+static int32 tablesize;
++static uint32 tablesize;
 +static int32 *sum_table;
  
 +#define gettag2(s1,s2) gettag((s1) + ((s2)<<16))
@@ -47,15 +47,15 @@ An extended version of a patch by Shachar Shemesh.
  
  static void build_hash_table(struct sum_struct *s)
  {
--      int32 i;
-+      int32 i, prior_size = tablesize;
+       int32 i;
++      uint32 prior_size = tablesize;
  
 -      if (!tag_table)
 -              tag_table = new_array(int32, TABLESIZE);
 +      /* Dynamically calculate the hash table size so that the hash load
 +       * for big files is about 80%.  This number must be odd or s2 will
 +       * not be able to span the entire set. */
-+      tablesize = (s->count/8) * 10 + 11;
++      tablesize = (uint32)(s->count/8) * 10 + 11;
 +      if (tablesize < 65537)
 +              tablesize = 65537; /* a prime number */
 +      if (tablesize != prior_size) {
@@ -73,7 +73,7 @@ An extended version of a patch by Shachar Shemesh.
        for (i = 0; i < s->count; i++) {
 -              targets[i].i = i;
 -              targets[i].t = gettag(s->sums[i].sum1);
-+              int32 t = gettag(s->sums[i].sum1);
++              uint32 t = gettag(s->sums[i].sum1);
 +              s->sums[i].chain = sum_table[t];
 +              sum_table[t] = i;
        }
@@ -88,14 +88,15 @@ An extended version of a patch by Shachar Shemesh.
  }
  
  
-@@ -176,20 +160,16 @@ static void hash_search(int f,struct sum
+@@ -176,20 +161,17 @@ static void hash_search(int f,struct sum
        }
  
        do {
 -              tag t = gettag2(s1,s2);
-+              int32 i, t = gettag2(s1,s2);
++              uint32 t = gettag2(s1,s2);
                int done_csum2 = 0;
 -              int32 j = tag_table[t];
++              int32 i;
  
                if (verbose > 4)
                        rprintf(FINFO,"offset=%.0f sum=%08x\n",(double)offset,sum);
@@ -112,7 +113,7 @@ An extended version of a patch by Shachar Shemesh.
  
                        if (sum != s->sums[i].sum1)
                                continue;
-@@ -205,9 +185,10 @@ static void hash_search(int f,struct sum
+@@ -205,9 +187,10 @@ static void hash_search(int f,struct sum
                            && !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
                                continue;
  
@@ -126,7 +127,7 @@ An extended version of a patch by Shachar Shemesh.
  
                        if (!done_csum2) {
                                map = (schar *)map_ptr(buf,offset,l);
-@@ -224,23 +205,23 @@ static void hash_search(int f,struct sum
+@@ -224,23 +207,23 @@ static void hash_search(int f,struct sum
                         * one with an identical offset, so we prefer that over
                         * the following want_i optimization. */
                        if (updating_basis_file) {
@@ -155,7 +156,7 @@ An extended version of a patch by Shachar Shemesh.
                        }
  
                        /* we've found a match, but now check to see
-@@ -266,9 +247,8 @@ static void hash_search(int f,struct sum
+@@ -266,9 +249,8 @@ static void hash_search(int f,struct sum
                        s2 = sum >> 16;
                        matches++;
                        break;
@@ -166,7 +167,7 @@ An extended version of a patch by Shachar Shemesh.
                backup = offset - last_match;
                /* We sometimes read 1 byte prior to last_match... */
                if (backup < 0)
-@@ -375,11 +355,6 @@ void match_sums(int f, struct sum_struct
+@@ -375,11 +357,6 @@ void match_sums(int f, struct sum_struct
                rprintf(FINFO,"sending file_sum\n");
        write_buf(f,file_sum,MD4_SUM_LENGTH);