Merge branch 'cc/skip' into HEAD

* cc/skip:
  Bisect: add "skip" to the short usage string.
  Bisect run: "skip" current commit if script exit code is 125.
  Bisect: add a "bisect replay" test case.
  Bisect: add "bisect skip" to the documentation.
  Bisect: refactor "bisect_{bad,good,skip}" into "bisect_state".
  Bisect: refactor some logging into "bisect_write".
  Bisect: refactor "bisect_write_*" functions.
  Bisect: implement "bisect skip" to mark untestable revisions.
  Bisect: fix some white spaces and empty lines breakages.
  rev-list documentation: add "--bisect-all".
  rev-list: implement --bisect-all

Documentation/git-bisect.txt

@@ -16,8 +16,9 @@ The command takes various subcommands, and different options depending
 on the subcommand:
 
  git bisect start [<bad> [<good>...]] [--] [<paths>...]
- git bisect bad <rev>
- git bisect good <rev>
+ git bisect bad [<rev>]
+ git bisect good [<rev>...]
+ git bisect skip [<rev>...]
  git bisect reset [<branch>]
  git bisect visualize
  git bisect replay <logfile>
@@ -134,6 +135,20 @@ $ git reset --hard HEAD~3		# try 3 revs before what
 Then compile and test the one you chose to try. After that, tell
 bisect what the result was as usual.
 
+Bisect skip
+~~~~~~~~~~~~
+
+Instead of choosing by yourself a nearby commit, you may just want git
+to do it for you using:
+
+------------
+$ git bisect skip                 # Current version cannot be tested
+------------
+
+But computing the commit to test may be slower afterwards and git may
+eventually not be able to tell the first bad among a bad and one or
+more "skip"ped commits.
+
 Cutting down bisection by giving more parameters to bisect start
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -167,14 +182,18 @@ $ git bisect run my_script
 ------------
 
 Note that the "run" script (`my_script` in the above example) should
-exit with code 0 in case the current source code is good and with a
-code between 1 and 127 (included) in case the current source code is
-bad.
+exit with code 0 in case the current source code is good.  Exit with a
+code between 1 and 127 (inclusive), except 125, if the current
+source code is bad.
 
 Any other exit code will abort the automatic bisect process. (A
 program that does "exit(-1)" leaves $? = 255, see exit(3) manual page,
 the value is chopped with "& 0377".)
 
+The special exit code 125 should be used when the current source code
+cannot be tested. If the "run" script exits with this code, the current
+revision will be skipped, see `git bisect skip` above.
+
 You may often find that during bisect you want to have near-constant
 tweaks (e.g., s/#define DEBUG 0/#define DEBUG 1/ in a header file, or
 "revision that does not have this commit needs this patch applied to

Documentation/git-rev-list.txt

@@ -34,6 +34,7 @@ SYNOPSIS
 	     [ \--pretty | \--header ]
 	     [ \--bisect ]
 	     [ \--bisect-vars ]
+	     [ \--bisect-all ]
 	     [ \--merge ]
 	     [ \--reverse ]
 	     [ \--walk-reflogs ]
@@ -354,6 +355,21 @@ the expected number of commits to be tested if `bisect_rev`
 turns out to be bad to `bisect_bad`, and the number of commits
 we are bisecting right now to `bisect_all`.
 
+--bisect-all::
+
+This outputs all the commit objects between the included and excluded
+commits, ordered by their distance to the included and excluded
+commits. The farthest from them is displayed first. (This is the only
+one displayed by `--bisect`.)
+
+This is useful because it makes it easy to choose a good commit to
+test when you want to avoid to test some of them for some reason (they
+may not compile for example).
+
+This option can be used along with `--bisect-vars`, in this case,
+after all the sorted commit objects, there will be the same text as if
+`--bisect-vars` had been used alone.
+
 --
 
 Commit Ordering

builtin-rev-list.c

@@ -9,6 +9,7 @@
 #include "revision.h"
 #include "list-objects.h"
 #include "builtin.h"
+#include "log-tree.h"
 
 /* bits #0-15 in revision.h */
 
@@ -38,7 +39,8 @@ static const char rev_list_usage[] =
 "    --left-right\n"
 "  special purpose:\n"
 "    --bisect\n"
-"    --bisect-vars"
+"    --bisect-vars\n"
+"    --bisect-all"
 ;
 
 static struct rev_info revs;
@@ -74,6 +76,7 @@ static void show_commit(struct commit *commit)
 			parents = parents->next;
 		}
 	}
+	show_decorations(commit);
 	if (revs.commit_format == CMIT_FMT_ONELINE)
 		putchar(' ');
 	else
@@ -278,6 +281,57 @@ static struct commit_list *best_bisection(struct commit_list *list, int nr)
 	return best;
 }
 
+struct commit_dist {
+	struct commit *commit;
+	int distance;
+};
+
+static int compare_commit_dist(const void *a_, const void *b_)
+{
+	struct commit_dist *a, *b;
+
+	a = (struct commit_dist *)a_;
+	b = (struct commit_dist *)b_;
+	if (a->distance != b->distance)
+		return b->distance - a->distance; /* desc sort */
+	return hashcmp(a->commit->object.sha1, b->commit->object.sha1);
+}
+
+static struct commit_list *best_bisection_sorted(struct commit_list *list, int nr)
+{
+	struct commit_list *p;
+	struct commit_dist *array = xcalloc(nr, sizeof(*array));
+	int cnt, i;
+
+	for (p = list, cnt = 0; p; p = p->next) {
+		int distance;
+		unsigned flags = p->item->object.flags;
+
+		if (revs.prune_fn && !(flags & TREECHANGE))
+			continue;
+		distance = weight(p);
+		if (nr - distance < distance)
+			distance = nr - distance;
+		array[cnt].commit = p->item;
+		array[cnt].distance = distance;
+		cnt++;
+	}
+	qsort(array, cnt, sizeof(*array), compare_commit_dist);
+	for (p = list, i = 0; i < cnt; i++) {
+		struct name_decoration *r = xmalloc(sizeof(*r) + 100);
+		struct object *obj = &(array[i].commit->object);
+
+		sprintf(r->name, "dist=%d", array[i].distance);
+		r->next = add_decoration(&name_decoration, obj, r);
+		p->item = array[i].commit;
+		p = p->next;
+	}
+	if (p)
+		p->next = NULL;
+	free(array);
+	return list;
+}
+
 /*
  * zero or positive weight is the number of interesting commits it can
  * reach, including itself.  Especially, weight = 0 means it does not
@@ -292,7 +346,8 @@ static struct commit_list *best_bisection(struct commit_list *list, int nr)
  * or positive distance.
  */
 static struct commit_list *do_find_bisection(struct commit_list *list,
-					     int nr, int *weights)
+					     int nr, int *weights,
+					     int find_all)
 {
 	int n, counted;
 	struct commit_list *p;
@@ -351,7 +406,7 @@ static struct commit_list *do_find_bisection(struct commit_list *list,
 		clear_distance(list);
 
 		/* Does it happen to be at exactly half-way? */
-		if (halfway(p, nr))
+		if (!find_all && halfway(p, nr))
 			return p;
 		counted++;
 	}
@@ -389,19 +444,22 @@ static struct commit_list *do_find_bisection(struct commit_list *list,
 				weight_set(p, weight(q));
 
 			/* Does it happen to be at exactly half-way? */
-			if (halfway(p, nr))
+			if (!find_all && halfway(p, nr))
 				return p;
 		}
 	}
 
 	show_list("bisection 2 counted all", counted, nr, list);
 
-	/* Then find the best one */
-	return best_bisection(list, nr);
+	if (!find_all)
+		return best_bisection(list, nr);
+	else
+		return best_bisection_sorted(list, nr);
 }
 
 static struct commit_list *find_bisection(struct commit_list *list,
-					  int *reaches, int *all)
+					  int *reaches, int *all,
+					  int find_all)
 {
 	int nr, on_list;
 	struct commit_list *p, *best, *next, *last;
@@ -434,14 +492,13 @@ static struct commit_list *find_bisection(struct commit_list *list,
 	weights = xcalloc(on_list, sizeof(*weights));
 
 	/* Do the real work of finding bisection commit. */
-	best = do_find_bisection(list, nr, weights);
-
+	best = do_find_bisection(list, nr, weights, find_all);
 	if (best) {
-		best->next = NULL;
+		if (!find_all)
+			best->next = NULL;
 		*reaches = weight(best);
 	}
 	free(weights);
-
 	return best;
 }
 
@@ -468,6 +525,7 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	int i;
 	int read_from_stdin = 0;
 	int bisect_show_vars = 0;
+	int bisect_find_all = 0;
 
 	git_config(git_default_config);
 	init_revisions(&revs, prefix);
@@ -490,6 +548,11 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			bisect_list = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--bisect-all")) {
+			bisect_list = 1;
+			bisect_find_all = 1;
+			continue;
+		}
 		if (!strcmp(arg, "--bisect-vars")) {
 			bisect_list = 1;
 			bisect_show_vars = 1;
@@ -536,9 +599,11 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	if (bisect_list) {
 		int reaches = reaches, all = all;
 
-		revs.commits = find_bisection(revs.commits, &reaches, &all);
+		revs.commits = find_bisection(revs.commits, &reaches, &all,
+					      bisect_find_all);
 		if (bisect_show_vars) {
 			int cnt;
+			char hex[41];
 			if (!revs.commits)
 				return 1;
 			/*
@@ -550,15 +615,22 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			 * A bisect set of size N has (N-1) commits further
 			 * to test, as we already know one bad one.
 			 */
-			cnt = all-reaches;
+			cnt = all - reaches;
 			if (cnt < reaches)
 				cnt = reaches;
+			strcpy(hex, sha1_to_hex(revs.commits->item->object.sha1));
+
+			if (bisect_find_all) {
+				traverse_commit_list(&revs, show_commit, show_object);
+				printf("------\n");
+			}
+
 			printf("bisect_rev=%s\n"
 			       "bisect_nr=%d\n"
 			       "bisect_good=%d\n"
 			       "bisect_bad=%d\n"
 			       "bisect_all=%d\n",
-			       sha1_to_hex(revs.commits->item->object.sha1),
+			       hex,
 			       cnt - 1,
 			       all - reaches - 1,
 			       reaches - 1,