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 bad [<rev>]
- git bisect good <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
+exit with code 0 in case the current source code is good.  Exit with a
-code between 1 and 127 (included) in case the current source code is
+code between 1 and 127 (inclusive), except 125, if the current
-bad.
+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 */
+	if (!find_all)
-	return best_bisection(list, nr);
+		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,

git-bisect.sh

@@ -1,12 +1,14 @@
 #!/bin/sh
 
-USAGE='[start|bad|good|next|reset|visualize|replay|log|run]'
+USAGE='[start|bad|good|skip|next|reset|visualize|replay|log|run]'
 LONG_USAGE='git bisect start [<bad> [<good>...]] [--] [<pathspec>...]
         reset bisect state and start bisection.
 git bisect bad [<rev>]
         mark <rev> a known-bad revision.
 git bisect good [<rev>...]
         mark <rev>... known-good revisions.
+git bisect skip [<rev>...]
+        mark <rev>... untestable revisions.
 git bisect next
         find next bisection to test and check it out.
 git bisect reset [<branch>]
@@ -64,7 +66,7 @@ bisect_start() {
 		    branch=`cat "$GIT_DIR/head-name"`
 		else
 		    branch=master
-	        fi
+		fi
 		git checkout $branch || exit
 		;;
 	refs/heads/*)
@@ -95,75 +97,74 @@ bisect_start() {
 	    arg="$1"
 	    case "$arg" in
 	    --)
-	        shift
+		shift
 		break
 		;;
 	    *)
-	        rev=$(git rev-parse --verify "$arg^{commit}" 2>/dev/null) || {
+		rev=$(git rev-parse --verify "$arg^{commit}" 2>/dev/null) || {
 		    test $has_double_dash -eq 1 &&
 		        die "'$arg' does not appear to be a valid revision"
 		    break
 		}
-		if [ $bad_seen -eq 0 ]; then
+		case $bad_seen in
-		    bad_seen=1
+		0) state='bad' ; bad_seen=1 ;;
-		    bisect_write_bad "$rev"
+		*) state='good' ;;
-		else
+		esac
-		    bisect_write_good "$rev"
+		bisect_write "$state" "$rev" 'nolog'
-		fi
+		shift
-	        shift
 		;;
 	    esac
-        done
+	done
 
 	sq "$@" >"$GIT_DIR/BISECT_NAMES"
 	echo "git-bisect start$orig_args" >>"$GIT_DIR/BISECT_LOG"
 	bisect_auto_next
 }
 
-bisect_bad() {
+bisect_write() {
+	state="$1"
+	rev="$2"
+	nolog="$3"
+	case "$state" in
+		bad)		tag="$state" ;;
+		good|skip)	tag="$state"-"$rev" ;;
+		*)		die "Bad bisect_write argument: $state" ;;
+	esac
+	echo "$rev" >"$GIT_DIR/refs/bisect/$tag"
+	echo "# $state: "$(git show-branch $rev) >>"$GIT_DIR/BISECT_LOG"
+	test -z "$nolog" && echo "git-bisect $state $rev" >>"$GIT_DIR/BISECT_LOG"
+}
+
+bisect_state() {
 	bisect_autostart
-	case "$#" in
+	state=$1
-	0)
+	case "$#,$state" in
-		rev=$(git rev-parse --verify HEAD) ;;
+	0,*)
-	1)
+		die "Please call 'bisect_state' with at least one argument." ;;
-		rev=$(git rev-parse --verify "$1^{commit}") ;;
+	1,bad|1,good|1,skip)
+		rev=$(git rev-parse --verify HEAD) ||
+			die "Bad rev input: HEAD"
+		bisect_write "$state" "$rev" ;;
+	2,bad)
+		rev=$(git rev-parse --verify "$2^{commit}") ||
+			die "Bad rev input: $2"
+		bisect_write "$state" "$rev" ;;
+	*,good|*,skip)
+		shift
+		revs=$(git rev-parse --revs-only --no-flags "$@") &&
+			test '' != "$revs" || die "Bad rev input: $@"
+		for rev in $revs
+		do
+			rev=$(git rev-parse --verify "$rev^{commit}") ||
+				die "Bad rev commit: $rev^{commit}"
+			bisect_write "$state" "$rev"
+		done ;;
 	*)
 		usage ;;
-	esac || exit
-	bisect_write_bad "$rev"
-	echo "git-bisect bad $rev" >>"$GIT_DIR/BISECT_LOG"
-	bisect_auto_next
-}
-
-bisect_write_bad() {
-	rev="$1"
-	echo "$rev" >"$GIT_DIR/refs/bisect/bad"
-	echo "# bad: "$(git show-branch $rev) >>"$GIT_DIR/BISECT_LOG"
-}
-
-bisect_good() {
-	bisect_autostart
-        case "$#" in
-	0)    revs=$(git rev-parse --verify HEAD) || exit ;;
-	*)    revs=$(git rev-parse --revs-only --no-flags "$@") &&
-		test '' != "$revs" || die "Bad rev input: $@" ;;
 	esac
-	for rev in $revs
-	do
-		rev=$(git rev-parse --verify "$rev^{commit}") || exit
-		bisect_write_good "$rev"
-		echo "git-bisect good $rev" >>"$GIT_DIR/BISECT_LOG"
-
-	done
 	bisect_auto_next
 }
 
-bisect_write_good() {
-	rev="$1"
-	echo "$rev" >"$GIT_DIR/refs/bisect/good-$rev"
-	echo "# good: "$(git show-branch $rev) >>"$GIT_DIR/BISECT_LOG"
-}
-
 bisect_next_check() {
 	missing_good= missing_bad=
 	git show-ref -q --verify refs/bisect/bad || missing_bad=t
@@ -206,17 +207,97 @@ bisect_auto_next() {
 	bisect_next_check && bisect_next || :
 }
 
+filter_skipped() {
+	_eval="$1"
+	_skip="$2"
+
+	if [ -z "$_skip" ]; then
+		eval $_eval
+		return
+	fi
+
+	# Let's parse the output of:
+	# "git rev-list --bisect-vars --bisect-all ..."
+	eval $_eval | while read hash line
+	do
+		case "$VARS,$FOUND,$TRIED,$hash" in
+			# We display some vars.
+			1,*,*,*) echo "$hash $line" ;;
+
+			# Split line.
+			,*,*,---*) ;;
+
+			# We had nothing to search.
+			,,,bisect_rev*)
+				echo "bisect_rev="
+				VARS=1
+				;;
+
+			# We did not find a good bisect rev.
+			# This should happen only if the "bad"
+			# commit is also a "skip" commit.
+			,,*,bisect_rev*)
+				echo "bisect_rev=$TRIED"
+				VARS=1
+				;;
+
+			# We are searching.
+			,,*,*)
+				TRIED="${TRIED:+$TRIED|}$hash"
+				case "$_skip" in
+				*$hash*) ;;
+				*)
+					echo "bisect_rev=$hash"
+					echo "bisect_tried=\"$TRIED\""
+					FOUND=1
+					;;
+				esac
+				;;
+
+			# We have already found a rev to be tested.
+			,1,*,bisect_rev*) VARS=1 ;;
+			,1,*,*) ;;
+
+			# ???
+			*) die "filter_skipped error " \
+			    "VARS: '$VARS' " \
+			    "FOUND: '$FOUND' " \
+			    "TRIED: '$TRIED' " \
+			    "hash: '$hash' " \
+			    "line: '$line'"
+			;;
+		esac
+	done
+}
+
+exit_if_skipped_commits () {
+	_tried=$1
+	if expr "$_tried" : ".*[|].*" > /dev/null ; then
+		echo "There are only 'skip'ped commit left to test."
+		echo "The first bad commit could be any of:"
+		echo "$_tried" | sed -e 's/[|]/\n/g'
+		echo "We cannot bisect more!"
+		exit 2
+	fi
+}
+
 bisect_next() {
-        case "$#" in 0) ;; *) usage ;; esac
+	case "$#" in 0) ;; *) usage ;; esac
 	bisect_autostart
 	bisect_next_check good
 
+	skip=$(git for-each-ref --format='%(objectname)' \
+		"refs/bisect/skip-*" | tr '[\012]' ' ') || exit
+
+	BISECT_OPT=''
+	test -n "$skip" && BISECT_OPT='--bisect-all'
+
 	bad=$(git rev-parse --verify refs/bisect/bad) &&
 	good=$(git for-each-ref --format='^%(objectname)' \
 		"refs/bisect/good-*" | tr '[\012]' ' ') &&
-	eval="git rev-list --bisect-vars $good $bad --" &&
+	eval="git rev-list --bisect-vars $BISECT_OPT $good $bad --" &&
 	eval="$eval $(cat "$GIT_DIR/BISECT_NAMES")" &&
-	eval=$(eval "$eval") &&
+	eval=$(filter_skipped "$eval" "$skip") &&
 	eval "$eval" || exit
 
 	if [ -z "$bisect_rev" ]; then
@@ -224,11 +305,16 @@ bisect_next() {
 		exit 1
 	fi
 	if [ "$bisect_rev" = "$bad" ]; then
+		exit_if_skipped_commits "$bisect_tried"
 		echo "$bisect_rev is first bad commit"
 		git diff-tree --pretty $bisect_rev
 		exit 0
 	fi
 
+	# We should exit here only if the "bad"
+	# commit is also a "skip" commit (see above).
+	exit_if_skipped_commits "$bisect_rev"
+
 	echo "Bisecting: $bisect_nr revisions left to test after this"
 	echo "$bisect_rev" >"$GIT_DIR/refs/heads/new-bisect"
 	git checkout -q new-bisect || exit
@@ -250,12 +336,10 @@ bisect_reset() {
 	   else
 	       branch=master
 	   fi ;;
-	1) git show-ref --verify --quiet -- "refs/heads/$1" || {
+	1) git show-ref --verify --quiet -- "refs/heads/$1" ||
-	       echo >&2 "$1 does not seem to be a valid branch"
+	       die "$1 does not seem to be a valid branch"
-	       exit 1
-	   }
 	   branch="$1" ;;
-        *)
+	*)
 	    usage ;;
 	esac
 	if git checkout "$branch"; then
@@ -273,10 +357,7 @@ bisect_clean_state() {
 }
 
 bisect_replay () {
-	test -r "$1" || {
+	test -r "$1" || die "cannot read $1 for replaying"
-		echo >&2 "cannot read $1 for replaying"
-		exit 1
-	}
 	bisect_reset
 	while read bisect command rev
 	do
@@ -284,21 +365,11 @@ bisect_replay () {
 		case "$command" in
 		start)
 			cmd="bisect_start $rev"
-			eval "$cmd"
+			eval "$cmd" ;;
-			;;
+		good|bad|skip)
-		good)
+			bisect_write "$command" "$rev" ;;
-			echo "$rev" >"$GIT_DIR/refs/bisect/good-$rev"
-			echo "# good: "$(git show-branch $rev) >>"$GIT_DIR/BISECT_LOG"
-			echo "git-bisect good $rev" >>"$GIT_DIR/BISECT_LOG"
-			;;
-		bad)
-			echo "$rev" >"$GIT_DIR/refs/bisect/bad"
-			echo "# bad: "$(git show-branch $rev) >>"$GIT_DIR/BISECT_LOG"
-			echo "git-bisect bad $rev" >>"$GIT_DIR/BISECT_LOG"
-			;;
 		*)
-			echo >&2 "?? what are you talking about?"
+			die "?? what are you talking about?" ;;
-			exit 1 ;;
 		esac
 	done <"$1"
 	bisect_auto_next
@@ -320,24 +391,31 @@ bisect_run () {
 	  exit $res
       fi
 
-      # Use "bisect_good" or "bisect_bad"
+      # Find current state depending on run success or failure.
-      # depending on run success or failure.
+      # A special exit code of 125 means cannot test.
-      if [ $res -gt 0 ]; then
+      if [ $res -eq 125 ]; then
-	  next_bisect='bisect_bad'
+	  state='skip'
+      elif [ $res -gt 0 ]; then
+	  state='bad'
       else
-	  next_bisect='bisect_good'
+	  state='good'
       fi
 
-      # We have to use a subshell because bisect_good or
+      # We have to use a subshell because "bisect_state" can exit.
-      # bisect_bad functions can exit.
+      ( bisect_state $state > "$GIT_DIR/BISECT_RUN" )
-      ( $next_bisect > "$GIT_DIR/BISECT_RUN" )
       res=$?
 
       cat "$GIT_DIR/BISECT_RUN"
 
+      if grep "first bad commit could be any of" "$GIT_DIR/BISECT_RUN" \
+		> /dev/null; then
+	  echo >&2 "bisect run cannot continue any more"
+	  exit $res
+      fi
+
       if [ $res -ne 0 ]; then
 	  echo >&2 "bisect run failed:"
-	  echo >&2 "$next_bisect exited with error code $res"
+	  echo >&2 "'bisect_state $state' exited with error code $res"
 	  exit $res
       fi
 
@@ -359,10 +437,8 @@ case "$#" in
     case "$cmd" in
     start)
         bisect_start "$@" ;;
-    bad)
+    bad|good|skip)
-        bisect_bad "$@" ;;
+        bisect_state "$cmd" "$@" ;;
-    good)
-        bisect_good "$@" ;;
     next)
         # Not sure we want "next" at the UI level anymore.
         bisect_next "$@" ;;

log-tree.c

@@ -15,7 +15,7 @@ static void show_parents(struct commit *commit, int abbrev)
 	}
 }
 
-static void show_decorations(struct commit *commit)
+void show_decorations(struct commit *commit)
 {
 	const char *prefix;
 	struct name_decoration *decoration;

log-tree.h

@@ -12,5 +12,6 @@ int log_tree_diff_flush(struct rev_info *);
 int log_tree_commit(struct rev_info *, struct commit *);
 int log_tree_opt_parse(struct rev_info *, const char **, int);
 void show_log(struct rev_info *opt, const char *sep);
+void show_decorations(struct commit *commit);
 
 #endif

t/t6030-bisect-porcelain.sh

@@ -71,6 +71,63 @@ test_expect_success 'bisect start with one bad and good' '
 	git bisect next
 '
 
+# $HASH1 is good, $HASH4 is bad, we skip $HASH3
+# but $HASH2 is bad,
+# so we should find $HASH2 as the first bad commit
+test_expect_success 'bisect skip: successfull result' '
+	git bisect reset &&
+	git bisect start $HASH4 $HASH1 &&
+	git bisect skip &&
+	git bisect bad > my_bisect_log.txt &&
+	grep "$HASH2 is first bad commit" my_bisect_log.txt &&
+	git bisect reset
+'
+
+# $HASH1 is good, $HASH4 is bad, we skip $HASH3 and $HASH2
+# so we should not be able to tell the first bad commit
+# among $HASH2, $HASH3 and $HASH4
+test_expect_success 'bisect skip: cannot tell between 3 commits' '
+	git bisect start $HASH4 $HASH1 &&
+	git bisect skip || return 1
+
+	if git bisect skip > my_bisect_log.txt
+	then
+		echo Oops, should have failed.
+		false
+	else
+		test $? -eq 2 &&
+		grep "first bad commit could be any of" my_bisect_log.txt &&
+		! grep $HASH1 my_bisect_log.txt &&
+		grep $HASH2 my_bisect_log.txt &&
+		grep $HASH3 my_bisect_log.txt &&
+		grep $HASH4 my_bisect_log.txt &&
+		git bisect reset
+	fi
+'
+
+# $HASH1 is good, $HASH4 is bad, we skip $HASH3
+# but $HASH2 is good,
+# so we should not be able to tell the first bad commit
+# among $HASH3 and $HASH4
+test_expect_success 'bisect skip: cannot tell between 2 commits' '
+	git bisect start $HASH4 $HASH1 &&
+	git bisect skip || return 1
+
+	if git bisect good > my_bisect_log.txt
+	then
+		echo Oops, should have failed.
+		false
+	else
+		test $? -eq 2 &&
+		grep "first bad commit could be any of" my_bisect_log.txt &&
+		! grep $HASH1 my_bisect_log.txt &&
+		! grep $HASH2 my_bisect_log.txt &&
+		grep $HASH3 my_bisect_log.txt &&
+		grep $HASH4 my_bisect_log.txt &&
+		git bisect reset
+	fi
+'
+
 # We want to automatically find the commit that
 # introduced "Another" into hello.
 test_expect_success \
@@ -99,6 +156,67 @@ test_expect_success \
      grep "$HASH4 is first bad commit" my_bisect_log.txt &&
      git bisect reset'
 
+# $HASH1 is good, $HASH5 is bad, we skip $HASH3
+# but $HASH4 is good,
+# so we should find $HASH5 as the first bad commit
+HASH5=
+test_expect_success 'bisect skip: add line and then a new test' '
+	add_line_into_file "5: Another new line." hello &&
+	HASH5=$(git rev-parse --verify HEAD) &&
+	git bisect start $HASH5 $HASH1 &&
+	git bisect skip &&
+	git bisect good > my_bisect_log.txt &&
+	grep "$HASH5 is first bad commit" my_bisect_log.txt &&
+	git bisect log > log_to_replay.txt
+	git bisect reset
+'
+
+test_expect_success 'bisect skip and bisect replay' '
+	git bisect replay log_to_replay.txt > my_bisect_log.txt &&
+	grep "$HASH5 is first bad commit" my_bisect_log.txt &&
+	git bisect reset
+'
+
+HASH6=
+test_expect_success 'bisect run & skip: cannot tell between 2' '
+	add_line_into_file "6: Yet a line." hello &&
+	HASH6=$(git rev-parse --verify HEAD) &&
+	echo "#"\!"/bin/sh" > test_script.sh &&
+	echo "tail -1 hello | grep Ciao > /dev/null && exit 125" >> test_script.sh &&
+	echo "grep line hello > /dev/null" >> test_script.sh &&
+	echo "test \$? -ne 0" >> test_script.sh &&
+	chmod +x test_script.sh &&
+	git bisect start $HASH6 $HASH1 &&
+	if git bisect run ./test_script.sh > my_bisect_log.txt
+	then
+		echo Oops, should have failed.
+		false
+	else
+		test $? -eq 2 &&
+		grep "first bad commit could be any of" my_bisect_log.txt &&
+		! grep $HASH3 my_bisect_log.txt &&
+		! grep $HASH6 my_bisect_log.txt &&
+		grep $HASH4 my_bisect_log.txt &&
+		grep $HASH5 my_bisect_log.txt
+	fi
+'
+
+HASH7=
+test_expect_success 'bisect run & skip: find first bad' '
+	git bisect reset &&
+	add_line_into_file "7: Should be the last line." hello &&
+	HASH7=$(git rev-parse --verify HEAD) &&
+	echo "#"\!"/bin/sh" > test_script.sh &&
+	echo "tail -1 hello | grep Ciao > /dev/null && exit 125" >> test_script.sh &&
+	echo "tail -1 hello | grep day > /dev/null && exit 125" >> test_script.sh &&
+	echo "grep Yet hello > /dev/null" >> test_script.sh &&
+	echo "test \$? -ne 0" >> test_script.sh &&
+	chmod +x test_script.sh &&
+	git bisect start $HASH7 $HASH1 &&
+	git bisect run ./test_script.sh > my_bisect_log.txt &&
+	grep "$HASH6 is first bad commit" my_bisect_log.txt
+'
+
 #
 #
 test_done