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 test_expect_success \
  81     '3-way merge with git-read-tree -m' \
  82     "git-read-tree -m $tree_O $tree_A $tree_B"
  83
  84 strip_object_id='s/^\([0-7]*\) [0-9a-f]* \([0-3].*\)$/\1 \2/'
  85
  86 test_expect_success \
  87     'git-ls-files --stage of the merge result' \
  88     'git-ls-files --stage >current- &&
  89      sed -e "$strip_object_id" <current- >current'
  90
  91 cat >expected <<\EOF
  92 100644 2 AA
  93 100644 3 AA
  94 100644 2 AN
  95 100644 1 DD
  96 100644 3 DF
  97 100644 2 DF/DF
  98 100644 1 DM
  99 100644 3 DM
 100 100644 1 DN
 101 100644 3 DN
 102 100644 2 LL
 103 100644 3 LL
 104 100644 1 MD
 105 100644 2 MD
 106 100644 1 MM
 107 100644 2 MM
 108 100644 3 MM
 109 100644 0 MN
 110 100644 3 NA
 111 100644 1 ND
 112 100644 2 ND
 113 100644 0 NM
 114 100644 0 NN
 115 100644 0 SS
 116 100644 1 TT
 117 100644 2 TT
 118 100644 3 TT
 119 100644 2 Z/AA
 120 100644 3 Z/AA
 121 100644 2 Z/AN
 122 100644 1 Z/DD
 123 100644 1 Z/DM
 124 100644 3 Z/DM
 125 100644 1 Z/DN
 126 100644 3 Z/DN
 127 100644 1 Z/MD
 128 100644 2 Z/MD
 129 100644 1 Z/MM
 130 100644 2 Z/MM
 131 100644 3 Z/MM
 132 100644 0 Z/MN
 133 100644 3 Z/NA
 134 100644 1 Z/ND
 135 100644 2 Z/ND
 136 100644 0 Z/NM
 137 100644 0 Z/NN
 138 EOF
 139
 140 test_expect_success \
 141     'validate merge result' \
 142     'diff current expected'
 143
 144 test_done