scripts/git: Add test branch support to the git scripts

Add a -t <test-branch-prefix> argument to git-merge-forward.sh and
git-push-all.sh, which makes these scripts create, merge forward, and
push test branches.

Add a -r <remote-name> argument to git-push-all.sh, so the script can
push test branches to a personal remote.

Closes ticket 31314.

changes/ticket31314

@@ -0,0 +1,6 @@
+  o Minor features (git scripts):
+    - Add a -t <test-branch-prefix> argument to git-merge-forward.sh and
+      git-push-all.sh, which makes these scripts create, merge forward, and
+      push test branches. Closes ticket 31314.
+    - Add a -r <remote-name> argument to git-push-all.sh, so the script can
+      push test branches to a personal remote. Closes ticket 31314.

scripts/git/git-merge-forward.sh

@@ -33,20 +33,45 @@ TOR_WKT_NAME=${TOR_WKT_NAME:-"tor-wkt"}
 # Configuration of the branches that needs merging. The values are in order:
 #   (0) current maint/release branch name
 #   (1) previous maint/release name to merge into (0)
+#         (only used in merge forward mode)
 #   (2) Full path of the git worktree
+#   (3) current branch suffix
+#         (maint branches only, only used in test branch mode)
+#   (4) previous test branch suffix to merge into (3)
+#         (maint branches only, only used in test branch mode)
 #
-# As an example:
+# Merge forward example:
 #   $ cd <PATH/TO/WORKTREE> (2)
 #   $ git checkout maint-0.3.5 (0)
 #   $ git pull
 #   $ git merge maint-0.3.4 (1)
 #
+# Test branch example:
+#   $ cd <PATH/TO/WORKTREE> (2)
+#   $ git checkout -b ticket99999_035 (3)
+#   $ git checkout maint-0.3.5 (0)
+#   $ git pull
+#   $ git checkout ticket99999_035
+#   $ git merge maint-0.3.5
+#   $ git merge ticket99999_034 (4)
+#
 # First set of arrays are the maint-* branch and then the release-* branch.
 # New arrays need to be in the WORKTREE= array else they aren't considered.
-MAINT_035=( "maint-0.3.5" "maint-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/maint-0.3.5" )
-MAINT_040=( "maint-0.4.0" "maint-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.0" )
-MAINT_041=( "maint-0.4.1" "maint-0.4.0" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.1" )
-MAINT_MASTER=( "master" "maint-0.4.1" "$GIT_PATH/$TOR_MASTER_NAME" )
+#
+# Only used in test branch mode
+# There is no previous branch to merge forward, so the second and fifth items
+# must be blank ("")
+MAINT_029_TB=( "maint-0.2.9" "" "$GIT_PATH/$TOR_WKT_NAME/maint-0.2.9" \
+    "_029" "")
+# Used in maint/release merge and test branch modes
+MAINT_035=( "maint-0.3.5" "maint-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/maint-0.3.5" \
+    "_035" "_029")
+MAINT_040=( "maint-0.4.0" "maint-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.0" \
+    "_040" "_035")
+MAINT_041=( "maint-0.4.1" "maint-0.4.0" "$GIT_PATH/$TOR_WKT_NAME/maint-0.4.1" \
+    "_041" "_040")
+MAINT_MASTER=( "master" "maint-0.4.1" "$GIT_PATH/$TOR_MASTER_NAME" \
+    "_master" "_041")
 
 RELEASE_029=( "release-0.2.9" "maint-0.2.9" "$GIT_PATH/$TOR_WKT_NAME/release-0.2.9" )
 RELEASE_035=( "release-0.3.5" "maint-0.3.5" "$GIT_PATH/$TOR_WKT_NAME/release-0.3.5" )
@@ -60,6 +85,7 @@ ORIGIN_PATH="$GIT_PATH/$TOR_MASTER_NAME"
 
 # SC2034 -- shellcheck thinks that these are unused.  We know better.
 ACTUALLY_THESE_ARE_USED=<<EOF
+${MAINT_029_TB[0]}
 ${MAINT_035[0]}
 ${MAINT_040[0]}
 ${MAINT_041[0]}
@@ -78,11 +104,19 @@ EOF
 # that would have been executed for each worktree.
 DRY_RUN=0
 
-while getopts "n" opt; do
+# Controlled by the -t <test-branch-prefix> option. The test branch base
+# name option makes git-merge-forward.sh create new test branches:
+# <tbbn>_029, <tbbn>_035, ... , <tbbn>_master, and merge forward.
+TEST_BRANCH_PREFIX=
+
+while getopts "nt:" opt; do
   case "$opt" in
     n) DRY_RUN=1
        echo "    *** DRY RUN MODE ***"
        ;;
+    t) TEST_BRANCH_PREFIX="$OPTARG"
+       echo "    *** CREATING TEST BRANCHES: ${TEST_BRANCH_PREFIX}_nnn ***"
+       ;;
     *)
        exit 1
        ;;
@@ -93,22 +127,44 @@ done
 # Git worktrees to manage #
 ###########################
 
-# List of all worktrees to work on. All defined above. Ordering is important.
-# Always the maint-* branch BEFORE then the release-*.
-WORKTREE=(
-  RELEASE_029[@]
+if [ -z "$TEST_BRANCH_PREFIX" ]; then
+
+  # maint/release merge mode
+  #
+  # List of all worktrees to work on. All defined above. Ordering is important.
+  # Always the maint-* branch BEFORE then the release-*.
+  WORKTREE=(
+    RELEASE_029[@]
+
+    MAINT_035[@]
+    RELEASE_035[@]
+
+    MAINT_040[@]
+    RELEASE_040[@]
+
+    MAINT_041[@]
+    RELEASE_041[@]
+
+    MAINT_MASTER[@]
+  )
+
+else
+
+  # Test branch mode: merge to maint only, and create a new branch for 0.2.9
+  WORKTREE=(
+    MAINT_029_TB[@]
+
+    MAINT_035[@]
 
-  MAINT_035[@]
-  RELEASE_035[@]
+    MAINT_040[@]
 
-  MAINT_040[@]
-  RELEASE_040[@]
+    MAINT_041[@]
 
-  MAINT_041[@]
-  RELEASE_041[@]
+    MAINT_MASTER[@]
+  )
+
+fi
 
-  MAINT_MASTER[@]
-)
 COUNT=${#WORKTREE[@]}
 
 #############
@@ -161,6 +217,19 @@ function switch_branch
   fi
 }
 
+# Checkout a new branch with the given branch name.
+function new_branch
+{
+  local cmd="git checkout -b $1"
+  printf "  %s Creating new branch %s..." "$MARKER" "$1"
+  if [ $DRY_RUN -eq 0 ]; then
+    msg=$( eval "$cmd" 2>&1 )
+    validate_ret $? "$msg"
+  else
+    printf "\\n      %s\\n" "${IWTH}$cmd${CNRM}"
+  fi
+}
+
 # Pull the given branch name.
 function pull_branch
 {
@@ -236,16 +305,51 @@ for ((i=0; i<COUNT; i++)); do
   current=${!WORKTREE[$i]:0:1}
   previous=${!WORKTREE[$i]:1:1}
   repo_path=${!WORKTREE[$i]:2:1}
+  # default to merge forward mode
+  test_current=
+  test_previous=
+  target_current="$current"
+  target_previous="$previous"
+  if [ "$TEST_BRANCH_PREFIX" ]; then
+    test_current_suffix=${!WORKTREE[$i]:3:1}
+    test_current=${TEST_BRANCH_PREFIX}${test_current_suffix}
+    # the current test branch, if present, or maint/release branch, if not
+    target_current="$test_current"
+    test_previous_suffix=${!WORKTREE[$i]:4:1}
+    if [ "$test_previous_suffix" ]; then
+      test_previous=${TEST_BRANCH_PREFIX}${test_previous_suffix}
+      # the previous test branch, if present, or maint/release branch, if not
+      target_previous="$test_previous"
+    fi
+  fi
 
-  printf "%s Handling branch \\n" "$MARKER" "${BYEL}$current${CNRM}"
+  printf "%s Handling branch \\n" "$MARKER" "${BYEL}$target${CNRM}"
 
   # Go into the worktree to start merging.
   goto_repo "$repo_path"
-  # Checkout the current branch
+  if [ "$test_current" ]; then
+    # Create a test branch from the currently checked-out branch/commit
+    new_branch "$test_current"
+  fi
+  # Checkout the current maint/release branch
   switch_branch "$current"
-  # Update the current branch with an origin merge to get the latest.
+  # Update the current maint/release branch with an origin merge to get the
+  # latest updates
   merge_branch_origin "$current"
-  # Example:
+  if [ "$test_current" ]; then
+    # Checkout the test branch
+    switch_branch "$test_current"
+    # Merge the updated maint branch into the test branch
+    merge_branch "$current" "$test_current"
+  fi
+  # Merge the previous branch into the target branch
+  # Merge Forward Example:
   #   merge maint-0.2.9 into maint-0.3.5.
-  merge_branch "$previous" "$current"
+  # Test Branch Example:
+  #   merge bug99999_029 into bug99999_035.
+  # Skip the merge if the previous branch does not exist
+  # (there's nothing to merge forward into the oldest test branch)
+  if [ "$target_previous" ]; then
+    merge_branch "$target_previous" "$target_current"
+  fi
 done

scripts/git/git-push-all.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-# Usage: git-push-all.sh <git-opts>
+# Usage: git-push-all.sh -t <test-branch-prefix> -r <remote-name> <git-opts>
 #        env vars: TOR_UPSTREAM_REMOTE_NAME=upstream TOR_PUSH_DELAY=0
 #        git-opts: --no-atomic --dry-run (any other git push option)
 #
@@ -17,10 +17,49 @@ set -e
 # Don't change this configuration - set the env vars in your .profile
 #
 # The upstream remote which git.torproject.org/tor.git points to.
+# In test branch mode, override this setting with -r <remote-name>
 UPSTREAM_REMOTE=${TOR_UPSTREAM_REMOTE_NAME:-"upstream"}
 # Add a delay between pushes, so CI runs on the most important branches first
 PUSH_DELAY=${TOR_PUSH_DELAY:-0}
 
+#######################
+# Argument processing #
+#######################
+
+# Controlled by the -t <test-branch-prefix> option. The test branch base
+# name option makes git-merge-forward.sh create new test branches:
+# <tbbn>_029, <tbbn>_035, ... , <tbbn>_master, and merge forward.
+TEST_BRANCH_PREFIX=
+
+while getopts ":r:t:" opt; do
+  case "$opt" in
+    r) UPSTREAM_REMOTE="$OPTARG"
+       echo "    *** PUSHING TO REMOTE: ${UPSTREAM_REMOTE} ***"
+       shift
+       shift
+       OPTIND=$[$OPTIND - 2]
+       ;;
+    t) TEST_BRANCH_PREFIX="$OPTARG"
+       echo "    *** PUSHING TEST BRANCHES: ${TEST_BRANCH_PREFIX}_nnn ***"
+       shift
+       shift
+       OPTIND=$[$OPTIND - 2]
+       ;;
+    *)
+       # Assume git push will handle the option
+       ;;
+  esac
+done
+
+if [ "$TEST_BRANCH_PREFIX" ]; then
+  if [ "$UPSTREAM_REMOTE" = ${TOR_UPSTREAM_REMOTE_NAME:-"upstream"} ]; then
+    echo "Pushing test branches ${TEST_BRANCH_PREFIX}_nnn to " \
+      "$UPSTREAM_REMOTE is not allowed."
+    echo "Usage: $0 -r <remote-name> -t <test-branch-prefix> <git-opts>"
+    exit 1
+  fi
+fi
+
 ########################
 # Git branches to push #
 ########################
@@ -33,6 +72,32 @@ PUSH_BRANCHES=$(echo \
   {release,maint}-0.2.9 \
   )
 
+if [ -z "$TEST_BRANCH_PREFIX" ]; then
+
+  # maint/release push mode
+  #
+  # List of branches to push. Ordering is not important.
+  PUSH_BRANCHES=$(echo \
+    master \
+    {release,maint}-0.4.1 \
+    {release,maint}-0.4.0 \
+    {release,maint}-0.3.5 \
+    {release,maint}-0.2.9 \
+    )
+else
+
+  # Test branch mode: merge to maint only, and create a new branch for 0.2.9
+  #
+  # List of branches to push. Ordering is not important.
+  PUSH_BRANCHES=$(echo \
+    ${TEST_BRANCH_PREFIX}_master \
+    ${TEST_BRANCH_PREFIX}_041 \
+    ${TEST_BRANCH_PREFIX}_040 \
+    ${TEST_BRANCH_PREFIX}_035 \
+    ${TEST_BRANCH_PREFIX}_029 \
+    )
+fi
+
 ###############
 # Entry point #
 ###############
@@ -48,18 +113,29 @@ if [ "$PUSH_DELAY" -le 0 ]; then
 else
   PUSH_BRANCHES=$(echo "$PUSH_BRANCHES" | tr " " "\n" | sort -V)
   MASTER_BRANCH=$(echo "$PUSH_BRANCHES" | tr " " "\n" | grep master)
-  MAINT_BRANCHES=$(echo "$PUSH_BRANCHES" | tr " " "\n" | grep maint)
-  RELEASE_BRANCHES=$(echo "$PUSH_BRANCHES" | tr " " "\n" | grep release | \
-    tr "\n" " ")
-  printf "Pushing with %ss delays, so CI runs in this order:\n%s\n%s\n%s\n" \
-    "$PUSH_DELAY" "$MASTER_BRANCH" "$MAINT_BRANCHES" "$RELEASE_BRANCHES"
+  if [ -z "$TEST_BRANCH_PREFIX" ]; then
+    MAINT_BRANCHES=$(echo "$PUSH_BRANCHES" | tr " " "\n" | grep maint)
+    RELEASE_BRANCHES=$(echo "$PUSH_BRANCHES" | tr " " "\n" | grep release | \
+      tr "\n" " ")
+    printf "Pushing with %ss delays, so CI runs in this order:\n%s\n%s\n%s\n" \
+      "$PUSH_DELAY" "$MASTER_BRANCH" "$MAINT_BRANCHES" "$RELEASE_BRANCHES"
+  else
+    # Actually test branches based on maint branches
+    MAINT_BRANCHES=$(echo "$PUSH_BRANCHES" | tr " " "\n" | grep -v master)
+    printf "Pushing with %ss delays, so CI runs in this order:\n%s\n%s\n" \
+      "$PUSH_DELAY" "$MASTER_BRANCH" "$MAINT_BRANCHES"
+    # No release branches
+    RELEASE_BRANCHES=
+  fi
   git push "$@" "$UPSTREAM_REMOTE" "$MASTER_BRANCH"
   sleep "$PUSH_DELAY"
   # shellcheck disable=SC2086
   for b in $MAINT_BRANCHES; do
-    git push "$@" "$UPSTREAM_REMOTE" $b
+    git push "$@" "$UPSTREAM_REMOTE" "$b"
     sleep "$PUSH_DELAY"
   done
-  # shellcheck disable=SC2086
-  git push --atomic "$@" "$UPSTREAM_REMOTE" $RELEASE_BRANCHES
+  if [ "$RELEASE_BRANCHES" ]; then
+    # shellcheck disable=SC2086
+    git push --atomic "$@" "$UPSTREAM_REMOTE" $RELEASE_BRANCHES
+  fi
 fi