t/t1000-read-tree-m-3way.sh

   1 #!/bin/sh
   2 #
   3 # Copyright (c) 2005 Junio C Hamano
   4 #
   5
   6 test_description='Three way merge with read-tree -m
   7
   8 This test tries three-way merge with read-tree -m
   9
  10 There is one ancestor (called O for Original) and two branches A
  11 and B derived from it.  We want to do a 3-way merge between A and
  12 B, using O as the common ancestor.
  13
  14     merge A O B
  15
  16 Decisions are made by comparing contents of O, A and B pathname
  17 by pathname.  The result is determined by the following guiding
  18 principle:
  19
  20  - If only A does something to it and B does not touch it, take
  21    whatever A does.
  22
  23  - If only B does something to it and A does not touch it, take
  24    whatever B does.
  25
  26  - If both A and B does something but in the same way, take
  27    whatever they do.
  28
  29  - If A and B does something but different things, we need a
  30    3-way merge:
  31
  32    - We cannot do anything about the following cases:
  33
  34      * O does not have it.  A and B both must be adding to the
  35        same path independently.
  36
  37      * A deletes it.  B must be modifying.
  38
  39    - Otherwise, A and B are modifying.  Run 3-way merge.
  40
  41 First, the case matrix.
  42
  43  - Vertical axis is for A'\''s actions.
  44  - Horizontal axis is for B'\''s actions.
  45
  46 .----------------------------------------------------------------.
  47 | A        B | No Action  |   Delete   |   Modify   |    Add     |
  48 |------------+------------+------------+------------+------------|
  49 | No Action  |            |            |            |            |
  50 |            | select O   | delete     | select B   | select B   |
  51 |            |            |            |            |            |
  52 |------------+------------+------------+------------+------------|
  53 | Delete     |            |            | ********** |    can     |
  54 |            | delete     | delete     | merge      |    not     |
  55 |            |            |            |            |  happen    |
  56 |------------+------------+------------+------------+------------|
  57 | Modify     |            | ********** | ?????????? |    can     |
  58 |            | select A   | merge      | select A=B |    not     |
  59 |            |            |            | merge      |  happen    |
  60 |------------+------------+------------+------------+------------|
  61 | Add        |            |    can     |    can     | ?????????? |
  62 |            | select A   |    not     |    not     | select A=B |
  63 |            |            |  happen    |  happen    | merge      |
  64 .----------------------------------------------------------------.
  65
  66 In addition:
  67
  68  SS: a special case of MM, where A and B makes the same modification.
  69  LL: a special case of AA, where A and B creates the same file.
  70  TT: a special case of MM, where A and B makes mergeable changes.
  71  DF: a special case, where A makes a directory and B makes a file.
  72
  73 '
  74 . ./test-lib.sh
  75 . ../lib-read-tree-m-3way.sh
  76
  77 ################################################################
  78 # Try merging and showing the various diffs
  79
  80 # The tree is dirty at this point.
  81 test_expect_failure \
  82     '3-way merge with git-read-tree -m' \
  83     "git-read-tree -m $tree_O $tree_A $tree_B"
  84
  85 # This is done on an empty work directory, which is the normal
  86 # merge person behaviour.
  87 test_expect_success \
  88     '3-way merge with git-read-tree -m' \
  89     "rm -fr [NDMALTS][NDMALTSF] Z &&
  90      rm .git/index &&
  91      git-read-tree -m $tree_O $tree_A $tree_B"
  92
  93 # This starts out with the first head, which is the normal
  94 # patch submitter behaviour.
  95 test_expect_success \
  96     '3-way merge with git-read-tree -m' \
  97     "git-read-tree $tree_A &&
  98      git-checkout-cache -f -u -a &&
  99      git-read-tree -m $tree_O $tree_A $tree_B"
 100
 101 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
 102 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
 103 test_expect_success \
 104     'git-ls-files --stage of the merge result' \
 105     'git-ls-files --stage >current- &&
 106      sed -e "s/ $_x40 / X /" <current- >current'
 107
 108 cat >expected <<\EOF
 109 100644 X 2      AA
 110 100644 X 3      AA
 111 100644 X 2      AN
 112 100644 X 1      DD
 113 100644 X 3      DF
 114 100644 X 2      DF/DF
 115 100644 X 1      DM
 116 100644 X 3      DM
 117 100644 X 1      DN
 118 100644 X 3      DN
 119 100644 X 2      LL
 120 100644 X 3      LL
 121 100644 X 1      MD
 122 100644 X 2      MD
 123 100644 X 1      MM
 124 100644 X 2      MM
 125 100644 X 3      MM
 126 100644 X 0      MN
 127 100644 X 3      NA
 128 100644 X 1      ND
 129 100644 X 2      ND
 130 100644 X 0      NM
 131 100644 X 0      NN
 132 100644 X 0      SS
 133 100644 X 1      TT
 134 100644 X 2      TT
 135 100644 X 3      TT
 136 100644 X 2      Z/AA
 137 100644 X 3      Z/AA
 138 100644 X 2      Z/AN
 139 100644 X 1      Z/DD
 140 100644 X 1      Z/DM
 141 100644 X 3      Z/DM
 142 100644 X 1      Z/DN
 143 100644 X 3      Z/DN
 144 100644 X 1      Z/MD
 145 100644 X 2      Z/MD
 146 100644 X 1      Z/MM
 147 100644 X 2      Z/MM
 148 100644 X 3      Z/MM
 149 100644 X 0      Z/MN
 150 100644 X 3      Z/NA
 151 100644 X 1      Z/ND
 152 100644 X 2      Z/ND
 153 100644 X 0      Z/NM
 154 100644 X 0      Z/NN
 155 EOF
 156
 157 test_expect_success \
 158     'validate merge result' \
 159     'diff current expected'
 160
 161 test_done