Merge pull request #7378

da6d18b devtools: replace github-merge with python version (Wladimir J. van der Laan)

4 files changed, 227 insertions, 189 deletions

diff --git a/contrib/README.md b/contrib/README.md
index 125594312b..b6e572102a 100644
--- a/contrib/README.md
+++ b/contrib/README.md
@@ -11,10 +11,10 @@ Repository Tools
 
 ### [Developer tools](/contrib/devtools) ###
 Specific tools for developers working on this repository.
-Contains the script `github-merge.sh` for merging github pull requests securely and signing them using GPG.
+Contains the script `github-merge.py` for merging github pull requests securely and signing them using GPG.
 
 ### [Verify-Commits](/contrib/verify-commits) ###
-Tool to verify that every merge commit was signed by a developer using the above `github-merge.sh` script.
+Tool to verify that every merge commit was signed by a developer using the above `github-merge.py` script.
 
 ### [Linearize](/contrib/linearize) ###
 Construct a linear, no-fork, best version of the blockchain.
diff --git a/contrib/devtools/README.md b/contrib/devtools/README.md
index fcb2275fc9..1103ca86c5 100644
--- a/contrib/devtools/README.md
+++ b/contrib/devtools/README.md
@@ -56,14 +56,14 @@ Usage: `git-subtree-check.sh DIR COMMIT`
 
 `COMMIT` may be omitted, in which case `HEAD` is used.
 
-github-merge.sh
+github-merge.py
 ===============
 
 A small script to automate merging pull-requests securely and sign them with GPG.
 
 For example:
 
-  ./github-merge.sh bitcoin/bitcoin 3077
+  ./github-merge.py 3077
 
 (in any git repository) will help you merge pull request #3077 for the
 bitcoin/bitcoin repository.
diff --git a/contrib/devtools/github-merge.py b/contrib/devtools/github-merge.py
new file mode 100755
index 0000000000..33d33b7005
--- /dev/null
+++ b/contrib/devtools/github-merge.py
@@ -0,0 +1,223 @@
+#!/usr/bin/env python2
+# Copyright (c) 2016 Bitcoin Core Developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+# This script will locally construct a merge commit for a pull request on a
+# github repository, inspect it, sign it and optionally push it.
+
+# The following temporary branches are created/overwritten and deleted:
+# * pull/$PULL/base (the current master we're merging onto)
+# * pull/$PULL/head (the current state of the remote pull request)
+# * pull/$PULL/merge (github's merge)
+# * pull/$PULL/local-merge (our merge)
+
+# In case of a clean merge that is accepted by the user, the local branch with
+# name $BRANCH is overwritten with the merged result, and optionally pushed.
+from __future__ import division,print_function,unicode_literals
+import os,sys
+from sys import stdin,stdout,stderr
+import argparse
+import subprocess
+
+# External tools (can be overridden using environment)
+GIT = os.getenv('GIT','git')
+BASH = os.getenv('BASH','bash')
+
+def git_config_get(option, default=None):
+    '''
+    Get named configuration option from git repository.
+    '''
+    try:
+        return subprocess.check_output([GIT,'config','--get',option]).rstrip()
+    except subprocess.CalledProcessError as e:
+        return default
+
+def retrieve_pr_title(repo,pull):
+    '''
+    Retrieve pull request title from github.
+    Return None if no title can be found, or an error happens.
+    '''
+    import urllib2,json
+    try:
+        req = urllib2.Request("https://api.github.com/repos/"+repo+"/pulls/"+pull)
+        result = urllib2.urlopen(req)
+        result = json.load(result)
+        return result['title']
+    except Exception as e:
+        print('Warning: unable to retrieve pull title from github: %s' % e)
+        return None
+
+def ask_prompt(text):
+    print(text,end=" ",file=stderr)
+    reply = stdin.readline().rstrip()
+    print("",file=stderr)
+    return reply
+
+def parse_arguments(branch):
+    epilog = '''
+        In addition, you can set the following git configuration variables:
+        githubmerge.repository (mandatory),
+        user.signingkey (mandatory),
+        githubmerge.host (default: git@github.com),
+        githubmerge.branch (default: master),
+        githubmerge.testcmd (default: none).
+    '''
+    parser = argparse.ArgumentParser(description='Utility to merge, sign and push github pull requests',
+            epilog=epilog)
+    parser.add_argument('pull', metavar='PULL', type=int, nargs=1,
+        help='Pull request ID to merge')
+    parser.add_argument('branch', metavar='BRANCH', type=str, nargs='?',
+        default=branch, help='Branch to merge against (default: '+branch+')')
+    return parser.parse_args()
+
+def main():
+    # Extract settings from git repo
+    repo = git_config_get('githubmerge.repository')
+    host = git_config_get('githubmerge.host','git@github.com')
+    branch = git_config_get('githubmerge.branch','master')
+    testcmd = git_config_get('githubmerge.testcmd')
+    signingkey = git_config_get('user.signingkey')
+    if repo is None:
+        print("ERROR: No repository configured. Use this command to set:", file=stderr)
+        print("git config githubmerge.repository <owner>/<repo>", file=stderr)
+        exit(1)
+    if signingkey is None:
+        print("ERROR: No GPG signing key set. Set one using:",file=stderr)
+        print("git config --global user.signingkey <key>",file=stderr)
+        exit(1)
+
+    host_repo = host+":"+repo # shortcut for push/pull target
+
+    # Extract settings from command line
+    args = parse_arguments(branch)
+    pull = str(args.pull[0])
+    branch = args.branch
+
+    # Initialize source branches
+    head_branch = 'pull/'+pull+'/head'
+    base_branch = 'pull/'+pull+'/base'
+    merge_branch = 'pull/'+pull+'/merge'
+    local_merge_branch = 'pull/'+pull+'/local-merge'
+
+    devnull = open(os.devnull,'w')
+    try:
+        subprocess.check_call([GIT,'checkout','-q',branch])
+    except subprocess.CalledProcessError as e:
+        print("ERROR: Cannot check out branch %s." % (branch), file=stderr)
+        exit(3)
+    try:
+        subprocess.check_call([GIT,'fetch','-q',host_repo,'+refs/pull/'+pull+'/*:refs/heads/pull/'+pull+'/*'])
+    except subprocess.CalledProcessError as e:
+        print("ERROR: Cannot find pull request #%s on %s." % (pull,host_repo), file=stderr)
+        exit(3)
+    try:
+        subprocess.check_call([GIT,'log','-q','-1','refs/heads/'+head_branch], stdout=devnull, stderr=stdout)
+    except subprocess.CalledProcessError as e:
+        print("ERROR: Cannot find head of pull request #%s on %s." % (pull,host_repo), file=stderr)
+        exit(3)
+    try:
+        subprocess.check_call([GIT,'log','-q','-1','refs/heads/'+merge_branch], stdout=devnull, stderr=stdout)
+    except subprocess.CalledProcessError as e:
+        print("ERROR: Cannot find merge of pull request #%s on %s." % (pull,host_repo), file=stderr)
+        exit(3)
+    try:
+        subprocess.check_call([GIT,'fetch','-q',host_repo,'+refs/heads/'+branch+':refs/heads/'+base_branch])
+    except subprocess.CalledProcessError as e:
+        print("ERROR: Cannot find branch %s on %s." % (branch,host_repo), file=stderr)
+        exit(3)
+    subprocess.check_call([GIT,'checkout','-q',base_branch])
+    subprocess.call([GIT,'branch','-q','-D',local_merge_branch], stderr=devnull)
+    subprocess.check_call([GIT,'checkout','-q','-b',local_merge_branch])
+
+    try:
+        # Create unsigned merge commit.
+        title = retrieve_pr_title(repo,pull)
+        if title:
+            firstline = 'Merge #%s: %s' % (pull,title)
+        else:
+            firstline = 'Merge #%s' % (pull,)
+        message = firstline + '\n\n'
+        message += subprocess.check_output([GIT,'log','--no-merges','--topo-order','--pretty=format:%h %s (%an)',base_branch+'..'+head_branch])
+        try:
+            subprocess.check_call([GIT,'merge','-q','--commit','--no-edit','--no-ff','-m',message,head_branch])
+        except subprocess.CalledProcessError as e:
+            print("ERROR: Cannot be merged cleanly.",file=stderr)
+            subprocess.check_call([GIT,'merge','--abort'])
+            exit(4)
+        logmsg = subprocess.check_output([GIT,'log','--pretty=format:%s','-n','1'])
+        if logmsg.rstrip() != firstline.rstrip():
+            print("ERROR: Creating merge failed (already merged?).",file=stderr)
+            exit(4)
+
+        # Run test command if configured.
+        if testcmd:
+            # Go up to the repository's root.
+            toplevel = subprocess.check_output([GIT,'rev-parse','--show-toplevel'])
+            os.chdir(toplevel)
+            if subprocess.call(testcmd,shell=True):
+                print("ERROR: Running %s failed." % testcmd,file=stderr)
+                exit(5)
+
+            # Show the created merge.
+            diff = subprocess.check_output([GIT,'diff',merge_branch+'..'+local_merge_branch])
+            subprocess.check_call([GIT,'diff',base_branch+'..'+local_merge_branch])
+            if diff:
+                print("WARNING: merge differs from github!",file=stderr)
+                reply = ask_prompt("Type 'ignore' to continue.")
+                if reply.lower() == 'ignore':
+                    print("Difference with github ignored.",file=stderr)
+                else:
+                    exit(6)
+            reply = ask_prompt("Press 'd' to accept the diff.")
+            if reply.lower() == 'd':
+                print("Diff accepted.",file=stderr)
+            else:
+                print("ERROR: Diff rejected.",file=stderr)
+                exit(6)
+        else:
+            # Verify the result manually.
+            print("Dropping you on a shell so you can try building/testing the merged source.",file=stderr)
+            print("Run 'git diff HEAD~' to show the changes being merged.",file=stderr)
+            print("Type 'exit' when done.",file=stderr)
+            if os.path.isfile('/etc/debian_version'): # Show pull number on Debian default prompt
+                os.putenv('debian_chroot',pull)
+            subprocess.call([BASH,'-i'])
+            reply = ask_prompt("Type 'm' to accept the merge.")
+            if reply.lower() == 'm':
+                print("Merge accepted.",file=stderr)
+            else:
+                print("ERROR: Merge rejected.",file=stderr)
+                exit(7)
+
+        # Sign the merge commit.
+        reply = ask_prompt("Type 's' to sign off on the merge.")
+        if reply == 's':
+            try:
+                subprocess.check_call([GIT,'commit','-q','--gpg-sign','--amend','--no-edit'])
+            except subprocess.CalledProcessError as e:
+                print("Error signing, exiting.",file=stderr)
+                exit(1)
+        else:
+            print("Not signing off on merge, exiting.",file=stderr)
+            exit(1)
+
+        # Put the result in branch.
+        subprocess.check_call([GIT,'checkout','-q',branch])
+        subprocess.check_call([GIT,'reset','-q','--hard',local_merge_branch])
+    finally:
+        # Clean up temporary branches.
+        subprocess.call([GIT,'checkout','-q',branch])
+        subprocess.call([GIT,'branch','-q','-D',head_branch],stderr=devnull)
+        subprocess.call([GIT,'branch','-q','-D',base_branch],stderr=devnull)
+        subprocess.call([GIT,'branch','-q','-D',merge_branch],stderr=devnull)
+        subprocess.call([GIT,'branch','-q','-D',local_merge_branch],stderr=devnull)
+
+    # Push the result.
+    reply = ask_prompt("Type 'push' to push the result to %s, branch %s." % (host_repo,branch))
+    if reply.lower() == 'push':
+        subprocess.check_call([GIT,'push',host_repo,'refs/heads/'+branch])
+
+if __name__ == '__main__':
+    main()
+
diff --git a/contrib/devtools/github-merge.sh b/contrib/devtools/github-merge.sh
deleted file mode 100755
index afb53f0390..0000000000
--- a/contrib/devtools/github-merge.sh
+++ /dev/null
@@ -1,185 +0,0 @@
-#!/bin/bash
-
-# This script will locally construct a merge commit for a pull request on a
-# github repository, inspect it, sign it and optionally push it.
-
-# The following temporary branches are created/overwritten and deleted:
-# * pull/$PULL/base (the current master we're merging onto)
-# * pull/$PULL/head (the current state of the remote pull request)
-# * pull/$PULL/merge (github's merge)
-# * pull/$PULL/local-merge (our merge)
-
-# In case of a clean merge that is accepted by the user, the local branch with
-# name $BRANCH is overwritten with the merged result, and optionally pushed.
-
-REPO="$(git config --get githubmerge.repository)"
-if [[ "d$REPO" == "d" ]]; then
-  echo "ERROR: No repository configured. Use this command to set:" >&2
-  echo "git config githubmerge.repository <owner>/<repo>" >&2
-  echo "In addition, you can set the following variables:" >&2
-  echo "- githubmerge.host (default git@github.com)" >&2
-  echo "- githubmerge.branch (default master)" >&2
-  echo "- githubmerge.testcmd (default none)" >&2
-  exit 1
-fi
-
-HOST="$(git config --get githubmerge.host)"
-if [[ "d$HOST" == "d" ]]; then
-  HOST="git@github.com"
-fi
-
-BRANCH="$(git config --get githubmerge.branch)"
-if [[ "d$BRANCH" == "d" ]]; then
-  BRANCH="master"
-fi
-
-TESTCMD="$(git config --get githubmerge.testcmd)"
-
-PULL="$1"
-
-if [[ "d$PULL" == "d" ]]; then
-  echo "Usage: $0 pullnumber [branch]" >&2
-  exit 2
-fi
-
-if [[ "d$2" != "d" ]]; then
-  BRANCH="$2"
-fi
-
-# Initialize source branches.
-git checkout -q "$BRANCH"
-if git fetch -q "$HOST":"$REPO" "+refs/pull/$PULL/*:refs/heads/pull/$PULL/*"; then
-  if ! git log -q -1 "refs/heads/pull/$PULL/head" >/dev/null 2>&1; then
-    echo "ERROR: Cannot find head of pull request #$PULL on $HOST:$REPO." >&2
-    exit 3
-  fi
-  if ! git log -q -1 "refs/heads/pull/$PULL/merge" >/dev/null 2>&1; then
-    echo "ERROR: Cannot find merge of pull request #$PULL on $HOST:$REPO." >&2
-    exit 3
-  fi
-else
-  echo "ERROR: Cannot find pull request #$PULL on $HOST:$REPO." >&2
-  exit 3
-fi
-if git fetch -q "$HOST":"$REPO" +refs/heads/"$BRANCH":refs/heads/pull/"$PULL"/base; then
-  true
-else
-  echo "ERROR: Cannot find branch $BRANCH on $HOST:$REPO." >&2
-  exit 3
-fi
-git checkout -q pull/"$PULL"/base
-git branch -q -D pull/"$PULL"/local-merge 2>/dev/null
-git checkout -q -b pull/"$PULL"/local-merge
-TMPDIR="$(mktemp -d -t ghmXXXXX)"
-
-function cleanup() {
-  git checkout -q "$BRANCH"
-  git branch -q -D pull/"$PULL"/head 2>/dev/null
-  git branch -q -D pull/"$PULL"/base 2>/dev/null
-  git branch -q -D pull/"$PULL"/merge 2>/dev/null
-  git branch -q -D pull/"$PULL"/local-merge 2>/dev/null
-  rm -rf "$TMPDIR"
-}
-
-# Create unsigned merge commit.
-(
-  echo "Merge pull request #$PULL"
-  echo ""
-  git log --no-merges --topo-order --pretty='format:%h %s (%an)' pull/"$PULL"/base..pull/"$PULL"/head
-)>"$TMPDIR/message"
-if git merge -q --commit --no-edit --no-ff -m "$(<"$TMPDIR/message")" pull/"$PULL"/head; then
-  if [ "d$(git log --pretty='format:%s' -n 1)" != "dMerge pull request #$PULL" ]; then
-    echo "ERROR: Creating merge failed (already merged?)." >&2
-    cleanup
-    exit 4
-  fi
-else
-  echo "ERROR: Cannot be merged cleanly." >&2
-  git merge --abort
-  cleanup
-  exit 4
-fi
-
-# Run test command if configured.
-if [[ "d$TESTCMD" != "d" ]]; then
-  # Go up to the repository's root.
-  while [ ! -d .git ]; do cd ..; done
-  if ! $TESTCMD; then
-    echo "ERROR: Running $TESTCMD failed." >&2
-    cleanup
-    exit 5
-  fi
-  # Show the created merge.
-  git diff pull/"$PULL"/merge..pull/"$PULL"/local-merge >"$TMPDIR"/diff
-  git diff pull/"$PULL"/base..pull/"$PULL"/local-merge
-  if [[ "$(<"$TMPDIR"/diff)" != "" ]]; then
-    echo "WARNING: merge differs from github!" >&2
-    read -p "Type 'ignore' to continue. " -r >&2
-    if [[ "d$REPLY" =~ ^d[iI][gG][nN][oO][rR][eE]$ ]]; then
-      echo "Difference with github ignored." >&2
-    else
-      cleanup
-      exit 6
-    fi
-  fi
-  read -p "Press 'd' to accept the diff. " -n 1 -r >&2
-  echo
-  if [[ "d$REPLY" =~ ^d[dD]$ ]]; then
-    echo "Diff accepted." >&2
-  else
-    echo "ERROR: Diff rejected." >&2
-    cleanup
-    exit 6
-  fi
-else
-  # Verify the result.
-  echo "Dropping you on a shell so you can try building/testing the merged source." >&2
-  echo "Run 'git diff HEAD~' to show the changes being merged." >&2
-  echo "Type 'exit' when done." >&2
-  if [[ -f /etc/debian_version ]]; then # Show pull number in prompt on Debian default prompt
-      export debian_chroot="$PULL"
-  fi
-  bash -i
-  read -p "Press 'm' to accept the merge. " -n 1 -r >&2
-  echo
-  if [[ "d$REPLY" =~ ^d[Mm]$ ]]; then
-    echo "Merge accepted." >&2
-  else
-    echo "ERROR: Merge rejected." >&2
-    cleanup
-    exit 7
-  fi
-fi
-
-# Sign the merge commit.
-read -p "Press 's' to sign off on the merge. " -n 1 -r >&2
-echo
-if [[ "d$REPLY" =~ ^d[Ss]$ ]]; then
-  if [[ "$(git config --get user.signingkey)" == "" ]]; then
-    echo "ERROR: No GPG signing key set, not signing. Set one using:" >&2
-    echo "git config --global user.signingkey <key>" >&2
-    cleanup
-    exit 1
-  else
-    if ! git commit -q --gpg-sign --amend --no-edit; then
-        echo "Error signing, exiting."
-        cleanup
-        exit 1
-    fi
-  fi
-else
-  echo "Not signing off on merge, exiting."
-  cleanup
-  exit 1
-fi
-
-# Clean up temporary branches, and put the result in $BRANCH.
-git checkout -q "$BRANCH"
-git reset -q --hard pull/"$PULL"/local-merge
-cleanup
-
-# Push the result.
-read -p "Type 'push' to push the result to $HOST:$REPO, branch $BRANCH. " -r >&2
-if [[ "d$REPLY" =~ ^d[Pp][Uu][Ss][Hh]$ ]]; then
-  git push "$HOST":"$REPO" refs/heads/"$BRANCH"
-fi