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Diffstat (limited to 'Documentation/git-patch-id.adoc')
| -rw-r--r-- | Documentation/git-patch-id.adoc | 71 |
1 files changed, 58 insertions, 13 deletions
diff --git a/Documentation/git-patch-id.adoc b/Documentation/git-patch-id.adoc index 92a1af36a2..05859990c8 100644 --- a/Documentation/git-patch-id.adoc +++ b/Documentation/git-patch-id.adoc @@ -3,7 +3,7 @@ git-patch-id(1) NAME ---- -git-patch-id - Compute unique ID for a patch +git-patch-id - Compute unique IDs for patches SYNOPSIS -------- @@ -12,7 +12,7 @@ git patch-id [--stable | --unstable | --verbatim] DESCRIPTION ----------- -Read a patch from the standard input and compute the patch ID for it. +Read patches from standard input and compute the patch IDs. A "patch ID" is nothing but a sum of SHA-1 of the file diffs associated with a patch, with line numbers ignored. As such, it's "reasonably stable", but at @@ -21,18 +21,19 @@ the same time also reasonably unique, i.e., two patches that have the same The main usecase for this command is to look for likely duplicate commits. -When dealing with `git diff-tree` output, it takes advantage of +When dealing with `git diff-tree --patch` output, it takes advantage of the fact that the patch is prefixed with the object name of the commit, and outputs two 40-byte hexadecimal strings. The first string is the patch ID, and the second string is the commit ID. -This can be used to make a mapping from patch ID to commit ID. +This can be used to make a mapping from patch ID to commit ID for a +set or range of commits. OPTIONS ------- `--verbatim`:: - Calculate the patch-id of the input as it is given, do not strip - any whitespace. + Calculate the patch ID of the input as it is given, do not strip + any whitespace. Implies `--stable` and forbids `--unstable`. + This is the default if `patchid.verbatim` is `true`. @@ -45,28 +46,72 @@ This is the default if `patchid.verbatim` is `true`. with two different settings for `-O<orderfile>` result in the same patch ID signature, thereby allowing the computed result to be used as a key to index some meta-information about the change between - the two trees; + the two trees. -- Result is different from the value produced by git 1.9 and older +- The result is different from the value produced by Git 1.9 and older or produced when an "unstable" hash (see `--unstable` below) is configured - even when used on a diff output taken without any use of `-O<orderfile>`, thereby making existing databases storing such - "unstable" or historical patch-ids unusable. + "unstable" or historical patch IDs unusable. -- All whitespace within the patch is ignored and does not affect the id. +- All whitespace within the patch is ignored and does not affect the ID. -- + This is the default if `patchid.stable` is set to `true`. `--unstable`:: Use an "unstable" hash as the patch ID. With this option, - the result produced is compatible with the patch-id value produced - by git 1.9 and older and whitespace is ignored. Users with pre-existing - databases storing patch-ids produced by git 1.9 and older (who do not deal + the result produced is compatible with the patch ID value produced + by Git 1.9 and older and whitespace is ignored. Users with pre-existing + databases storing patch IDs produced by Git 1.9 and older (who do not deal with reordered patches) may want to use this option. + This is the default. +EXAMPLES +-------- + +linkgit:git-cherry[1] shows what commits from a branch have patch ID +equivalent commits in some upstream branch. But it only tells you +whether such a commit exists or not. What if you wanted to know the +relevant commits in the upstream? We can use this command to make a +mapping between your branch and the upstream branch: + +---- +#!/bin/sh + +upstream="$1" +branch="$2" +test -z "$branch" && branch=HEAD +limit="$3" +if test -n "$limit" +then + tail_opts="$limit".."$upstream" +else + since=$(git log --format=%aI "$upstream".."$branch" | tail -1) + tail_opts=--since="$since"' '"$upstream" +fi +for_branch=$(mktemp) +for_upstream=$(mktemp) + +git rev-list --no-merges "$upstream".."$branch" | + git diff-tree --patch --stdin | + git patch-id --stable | sort >"$for_branch" +git rev-list --no-merges $tail_opts | + git diff-tree --patch --stdin | + git patch-id --stable | sort >"$for_upstream" +join -a1 "$for_branch" "$for_upstream" | cut -d' ' -f2,3 +rm "$for_branch" +rm "$for_upstream" +---- + +Now the first column shows the commit from your branch and the second +column shows the patch ID equivalent commit, if it exists. + +SEE ALSO +-------- +linkgit:git-cherry[1] + GIT --- Part of the linkgit:git[1] suite |