github.com/sfdevops1/terrra4orm@v0.11.12-beta1/config/module/test-fixtures/basic-git/DOTgit/hooks/pre-rebase.sample (about)

     1  #!/bin/sh
     2  #
     3  # Copyright (c) 2006, 2008 Junio C Hamano
     4  #
     5  # The "pre-rebase" hook is run just before "git rebase" starts doing
     6  # its job, and can prevent the command from running by exiting with
     7  # non-zero status.
     8  #
     9  # The hook is called with the following parameters:
    10  #
    11  # $1 -- the upstream the series was forked from.
    12  # $2 -- the branch being rebased (or empty when rebasing the current branch).
    13  #
    14  # This sample shows how to prevent topic branches that are already
    15  # merged to 'next' branch from getting rebased, because allowing it
    16  # would result in rebasing already published history.
    17  
    18  publish=next
    19  basebranch="$1"
    20  if test "$#" = 2
    21  then
    22  	topic="refs/heads/$2"
    23  else
    24  	topic=`git symbolic-ref HEAD` ||
    25  	exit 0 ;# we do not interrupt rebasing detached HEAD
    26  fi
    27  
    28  case "$topic" in
    29  refs/heads/??/*)
    30  	;;
    31  *)
    32  	exit 0 ;# we do not interrupt others.
    33  	;;
    34  esac
    35  
    36  # Now we are dealing with a topic branch being rebased
    37  # on top of master.  Is it OK to rebase it?
    38  
    39  # Does the topic really exist?
    40  git show-ref -q "$topic" || {
    41  	echo >&2 "No such branch $topic"
    42  	exit 1
    43  }
    44  
    45  # Is topic fully merged to master?
    46  not_in_master=`git rev-list --pretty=oneline ^master "$topic"`
    47  if test -z "$not_in_master"
    48  then
    49  	echo >&2 "$topic is fully merged to master; better remove it."
    50  	exit 1 ;# we could allow it, but there is no point.
    51  fi
    52  
    53  # Is topic ever merged to next?  If so you should not be rebasing it.
    54  only_next_1=`git rev-list ^master "^$topic" ${publish} | sort`
    55  only_next_2=`git rev-list ^master           ${publish} | sort`
    56  if test "$only_next_1" = "$only_next_2"
    57  then
    58  	not_in_topic=`git rev-list "^$topic" master`
    59  	if test -z "$not_in_topic"
    60  	then
    61  		echo >&2 "$topic is already up-to-date with master"
    62  		exit 1 ;# we could allow it, but there is no point.
    63  	else
    64  		exit 0
    65  	fi
    66  else
    67  	not_in_next=`git rev-list --pretty=oneline ^${publish} "$topic"`
    68  	/usr/bin/perl -e '
    69  		my $topic = $ARGV[0];
    70  		my $msg = "* $topic has commits already merged to public branch:\n";
    71  		my (%not_in_next) = map {
    72  			/^([0-9a-f]+) /;
    73  			($1 => 1);
    74  		} split(/\n/, $ARGV[1]);
    75  		for my $elem (map {
    76  				/^([0-9a-f]+) (.*)$/;
    77  				[$1 => $2];
    78  			} split(/\n/, $ARGV[2])) {
    79  			if (!exists $not_in_next{$elem->[0]}) {
    80  				if ($msg) {
    81  					print STDERR $msg;
    82  					undef $msg;
    83  				}
    84  				print STDERR " $elem->[1]\n";
    85  			}
    86  		}
    87  	' "$topic" "$not_in_next" "$not_in_master"
    88  	exit 1
    89  fi
    90  
    91  exit 0
    92  
    93  ################################################################
    94  
    95  This sample hook safeguards topic branches that have been
    96  published from being rewound.
    97  
    98  The workflow assumed here is:
    99  
   100   * Once a topic branch forks from "master", "master" is never
   101     merged into it again (either directly or indirectly).
   102  
   103   * Once a topic branch is fully cooked and merged into "master",
   104     it is deleted.  If you need to build on top of it to correct
   105     earlier mistakes, a new topic branch is created by forking at
   106     the tip of the "master".  This is not strictly necessary, but
   107     it makes it easier to keep your history simple.
   108  
   109   * Whenever you need to test or publish your changes to topic
   110     branches, merge them into "next" branch.
   111  
   112  The script, being an example, hardcodes the publish branch name
   113  to be "next", but it is trivial to make it configurable via
   114  $GIT_DIR/config mechanism.
   115  
   116  With this workflow, you would want to know:
   117  
   118  (1) ... if a topic branch has ever been merged to "next".  Young
   119      topic branches can have stupid mistakes you would rather
   120      clean up before publishing, and things that have not been
   121      merged into other branches can be easily rebased without
   122      affecting other people.  But once it is published, you would
   123      not want to rewind it.
   124  
   125  (2) ... if a topic branch has been fully merged to "master".
   126      Then you can delete it.  More importantly, you should not
   127      build on top of it -- other people may already want to
   128      change things related to the topic as patches against your
   129      "master", so if you need further changes, it is better to
   130      fork the topic (perhaps with the same name) afresh from the
   131      tip of "master".
   132  
   133  Let's look at this example:
   134  
   135  		   o---o---o---o---o---o---o---o---o---o "next"
   136  		  /       /           /           /
   137  		 /   a---a---b A     /           /
   138  		/   /               /           /
   139  	       /   /   c---c---c---c B         /
   140  	      /   /   /             \         /
   141  	     /   /   /   b---b C     \       /
   142  	    /   /   /   /             \     /
   143      ---o---o---o---o---o---o---o---o---o---o---o "master"
   144  
   145  
   146  A, B and C are topic branches.
   147  
   148   * A has one fix since it was merged up to "next".
   149  
   150   * B has finished.  It has been fully merged up to "master" and "next",
   151     and is ready to be deleted.
   152  
   153   * C has not merged to "next" at all.
   154  
   155  We would want to allow C to be rebased, refuse A, and encourage
   156  B to be deleted.
   157  
   158  To compute (1):
   159  
   160  	git rev-list ^master ^topic next
   161  	git rev-list ^master        next
   162  
   163  	if these match, topic has not merged in next at all.
   164  
   165  To compute (2):
   166  
   167  	git rev-list master..topic
   168  
   169  	if this is empty, it is fully merged to "master".