Merge branch 'sg/bash-prompt'

diff --git a/bisect.c b/bisect.c
index 7f95273e699418bd8a4c11ed6491eb8b6da434dc..71c19581daccffc87e5128c61d9adfae0be3e7de 100644 (file)
--- a/bisect.c
+++ b/bisect.c
@@ -15,7 +15,7 @@
 static struct sha1_array good_revs;
 static struct sha1_array skipped_revs;
 
-static const unsigned char *current_bad_sha1;
+static unsigned char *current_bad_sha1;
 
 static const char *argv_checkout[] = {"checkout", "-q", NULL, "--", NULL};
 static const char *argv_show_branch[] = {"show-branch", NULL, NULL};
@@ -404,7 +404,8 @@ static int register_ref(const char *refname, const unsigned char *sha1,
                        int flags, void *cb_data)
 {
        if (!strcmp(refname, "bad")) {
-               current_bad_sha1 = sha1;
+               current_bad_sha1 = xmalloc(20);
+               hashcpy(current_bad_sha1, sha1);
        } else if (!prefixcmp(refname, "good-")) {
                sha1_array_append(&good_revs, sha1);
        } else if (!prefixcmp(refname, "skip-")) {
@@ -956,3 +957,41 @@ int bisect_next_all(const char *prefix, int no_checkout)
        return bisect_checkout(bisect_rev_hex, no_checkout);
 }
 
+static inline int log2i(int n)
+{
+       int log2 = 0;
+
+       for (; n > 1; n >>= 1)
+               log2++;
+
+       return log2;
+}
+
+static inline int exp2i(int n)
+{
+       return 1 << n;
+}
+
+/*
+ * Estimate the number of bisect steps left (after the current step)
+ *
+ * For any x between 0 included and 2^n excluded, the probability for
+ * n - 1 steps left looks like:
+ *
+ * P(2^n + x) == (2^n - x) / (2^n + x)
+ *
+ * and P(2^n + x) < 0.5 means 2^n < 3x
+ */
+int estimate_bisect_steps(int all)
+{
+       int n, x, e;
+
+       if (all < 3)
+               return 0;
+
+       n = log2i(all);
+       e = exp2i(n);
+       x = all - e;
+
+       return (e < 3 * x) ? n : n - 1;
+}