@@ -16,25 +16,28 @@ struct tally {
size_t total;
/* This allows limited frequency analysis. */
unsigned buckets, step_bits;
-       size_t counts[1 /* [buckets] */ ];
+       size_t counts[1 /* Actually: [buckets] */ ];
};

struct tally *tally_new(unsigned buckets)
{
struct tally *tally;

+       /* There is always 1 bucket. */
+       if (buckets == 0)
+               buckets = 1;
+
/* Check for overflow. */
if (buckets && SIZE_MAX / buckets < sizeof(tally->counts))
return NULL;
-       tally = malloc(sizeof(*tally) + sizeof(tally->counts)*buckets);
+       tally = malloc(sizeof(*tally) + sizeof(tally->counts)*(buckets-1));
if (tally) {
tally->max = ((size_t)1 << (SIZET_BITS - 1));
tally->min = ~tally->max;
tally->total = tally->total = 0;
-               /* There is always 1 bucket. */
-               tally->buckets = buckets+1;
+               tally->buckets = buckets;
tally->step_bits = 0;
-               memset(tally->counts, 0, sizeof(tally->counts)*(buckets+1));
+               memset(tally->counts, 0, sizeof(tally->counts)*buckets);
}
return tally;
}
@@ -319,7 +322,7 @@ ssize_t tally_total(const struct tally *tally, ssize_t *overflow)
}

/* If result is negative, make sure we can represent it. */
-       if (tally->total & (1 << (SIZET_BITS-1))) {
+       if (tally->total & ((size_t)1 << (SIZET_BITS-1))) {
/* Must have only underflowed once, and must be able to
* represent result at ssize_t. */
if ((~tally->total)+1 != 0
@@ -422,7 +425,7 @@ char *tally_histogram(const struct tally *tally,
} else {
/* We create a temporary then renormalize so < height. */
/* FIXME: Antialias properly! */
-               tmp = tally_new(tally->buckets-1);
+               tmp = tally_new(tally->buckets);
if (!tmp)
return NULL;
tmp->min = tally->min;
@@ -452,14 +455,17 @@ char *tally_histogram(const struct tally *tally,
}

for (i = 0; i < height; i++) {
-               unsigned covered = 1;
-               count = (double)tally->counts[i] / largest_bucket * (width-1)+1;
+               unsigned covered = 1, row;
+
+               /* People expect minimum at the bottom. */
+               row = height - i - 1;
+               count = (double)tally->counts[row] / largest_bucket * (width-1)+1;

-               if (i == 0)
+               if (row == 0)
covered = snprintf(p, width, "%zi", tally->min);
-               else if (i == height - 1)
+               else if (row == height - 1)
covered = snprintf(p, width, "%zi", tally->max);
-               else if (i == bucket_of(tally->min, tally->step_bits, 0))
+               else if (row == bucket_of(tally->min, tally->step_bits, 0))
*p = '+';
else
*p = '|';