Documentation: bisect: add a few "git bisect run" examples

Before this patch, there were no "git bisect run" example.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-bisect.txt

@@ -224,6 +224,55 @@ tree to the pristine state.  Finally the "run" script can exit with
 the status of the real test to let "git bisect run" command loop to
 know the outcome.
 
+EXAMPLES
+--------
+
+* Automatically bisect a broken build between v1.2 and HEAD:
++
+------------
+$ git bisect start HEAD v1.2 --      # HEAD is bad, v1.2 is good
+$ git bisect run make                # "make" builds the app
+------------
+
+* Automatically bisect a broken test suite:
++
+------------
+$ cat ~/test.sh
+#!/bin/sh
+make || exit 125                   # this "skip"s broken builds
+make test                          # "make test" runs the test suite
+$ git bisect start v1.3 v1.1 --    # v1.3 is bad, v1.1 is good
+$ git bisect run ~/test.sh
+------------
++
+Here we use a "test.sh" custom script. In this script, if "make"
+fails, we "skip" the current commit.
++
+It's safer to use a custom script outside the repo to prevent
+interactions between the bisect, make and test processes and the
+script.
++
+And "make test" should "exit 0", if the test suite passes, and
+"exit 1" (for example) otherwise.
+
+* Automatically bisect a broken test case:
++
+------------
+$ cat ~/test.sh
+#!/bin/sh
+make || exit 125                     # this "skip"s broken builds
+~/check_test_case.sh                 # does the test case passes ?
+$ git bisect start HEAD HEAD~10 --   # culprit is among the last 10
+$ git bisect run ~/test.sh
+------------
++
+Here "check_test_case.sh" should "exit 0", if the test case passes,
+and "exit 1" (for example) otherwise.
++
+It's safer if both "test.sh" and "check_test_case.sh" scripts are
+outside the repo to prevent interactions between the bisect, make and
+test processes and the scripts.
+
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>