SHA1 ID of commits and trees. (in Japanese)

gistfile1.txt

# 内容は同じだけど履歴は違うけどブランチ master と two-phases を作る
% git init
Initialized empty Git repository in /private/tmp/myrepo/.git/
% touch ab.txt
% git add ab.txt; git commit -m 'a empty file'
[master (root-commit) 7d9d5ea] a empty file
 0 files changed, 0 insertions(+), 0 deletions(-)
 create mode 100644 ab.txt

% echo 'A\nB' > ab.txt
% git commit -am 'A and B'
[master c7091de] A and B
 1 files changed, 2 insertions(+), 0 deletions(-)

% git checkout -b two-phases HEAD~
% echo 'A' > ab.txt
% git commit -am 'A added'
[two-phases 4cf3183] A added
 1 files changed, 1 insertions(+), 0 deletions(-)
% echo 'B' >> ab.txt
% git commit -am 'B added'
[two-phases 246f617] B added
 1 files changed, 1 insertions(+), 0 deletions(-)

# ツリーは一緒
% git cat-file -p master
tree b4077185390b0ff9495a6db2122e9b478c50af08
parent 7d9d5ea99dcdf9e9c270dab09affc6d0c4705e46
author hiratara <hiratara@cpan.org> 1262937776 +0900
committer hiratara <hiratara@cpan.org> 1262937776 +0900

A and B


% git cat-file -p two-phases
tree b4077185390b0ff9495a6db2122e9b478c50af08
parent 4cf31836d3c5069bd5f12c68468369b9dbafaa29
author hiratara <hiratara@cpan.org> 1262937874 +0900
committer hiratara <hiratara@cpan.org> 1262937874 +0900

B added


# コミットのIDは別
% git rev-parse master
c7091de25d27cf53570cd850a72fde5e087aa122

% git rev-parse two-phases
246f6173aec6c82e9fbd2da14f8e9391aa179d15


# show-branch の結果
% git show-branch master two-phases
! [master] A and B
 * [two-phases] B added
--
 * [two-phases] B added
 * [two-phases^] A added
+  [master] A and B
+* [two-phases~2] a empty file


# 全く同じ履歴をshow-branchするとこう
% git show-branch master c7091de25d27
! [master] A and B
 ! [c7091de25d27] A and B
--
++ [master] A and B

% git show-branch two-phases 246f6173aec
* [two-phases] B added
 ! [246f6173aec] B added
--
*+ [two-phases] B added






# 念のため、master と two-phases に another ブランチをマージして show_branch する
% git checkout -b another HEAD~2
Switched to a new branch 'another'
% echo 'C' > c.txt
% git add c.txt; git commit -m "C added"
[another 8fafada] C added
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 c.txt

% git checkout master
Switched to branch 'master'
% git merge another
Merge made by recursive.
 c.txt |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 c.txt

% git checkout two-phases
Switched to branch 'two-phases'
% git merge another
Merge made by recursive.
 c.txt |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
 create mode 100644 c.txt

# show-barnch すると履歴は違いそう
% git show-branch master two-phases
! [master] Merge branch 'another'
 * [two-phases] Merge branch 'another' into two-phases
--
 - [two-phases] Merge branch 'another' into two-phases
 * [two-phases^] B added
 * [two-phases~2] A added
-  [master] Merge branch 'another'
+* [two-phases^2] C added

# でも、ツリーのSHA1は同じ
% git cat-file -p master
tree 0ef0528a594b679def8ed8910a66254fa7351adc
parent c7091de25d27cf53570cd850a72fde5e087aa122
parent 8fafadace4f525d2c20d9b29daecb34b3867bf05
author hiratara <hiratara@cpan.org> 1262938703 +0900
committer hiratara <hiratara@cpan.org> 1262938703 +0900

Merge branch 'another'

% git cat-file -p two-phases
tree 0ef0528a594b679def8ed8910a66254fa7351adc
parent 246f6173aec6c82e9fbd2da14f8e9391aa179d15
parent 8fafadace4f525d2c20d9b29daecb34b3867bf05
author hiratara <hiratara@cpan.org> 1262938741 +0900
committer hiratara <hiratara@cpan.org> 1262938741 +0900

Merge branch 'another' into two-phases