contrib: add script "nm-setup-git.sh" for setting up NetworkManager git repository

You can of course just clone NetworkManager repository and start hacking
as you like. However, there are a few things like git-notest which are
interesting to setup.

Add a script to do this.

The script is supposed to be idempotent and do nothing, unless
necessary. By default it also only prints what it would do.

contrib/scripts/nm-setup-git.sh

@@ -0,0 +1,115 @@
+#!/bin/bash
+
+set -e
+
+usage() {
+    printf "%s [--no-test]\n" "$CMD_NAME"
+    printf "\n"
+    printf "  --no-test: by default, the script only prints what it\n"
+    printf "    would do. You can also set NO_TEST=1 environment variable.\n"
+    printf "\n"
+}
+
+get_bool() {
+    local name="$1"
+    local val="${!name}"
+
+    case "$val" in
+        1|y|yes|Yes|YES|true|True|TRUE|on|On|ON)
+            echo -n 1
+            return 0
+            ;;
+        0|n|no|No|NO|false|False|FALSE|off|Off|OFF)
+            echo -n 0
+            return 0
+            ;;
+        *)
+            printf "%s" "$2"
+            ;;
+    esac
+}
+
+die() {
+    echo "ERROR: $*"
+    exit 1
+}
+
+call() {
+    local m=""
+
+    [ "$SKIP" = 1 ] && m="SKIP: "
+
+    if [ "$NO_TEST" != 1 ]; then
+        printf "WOULD: %s%s\n" "$m" "$*"
+        return 0
+    fi
+    printf "CALL: %s%s\n" "$m" "$*"
+    [ "$SKIP" = 1 ] || "$@"
+}
+
+git_config_reset() {
+    local key="$1"
+    local val="$2"
+    local c=(git config --replace-all "$key" "$val")
+
+    test "$#" == 2 || die "invalid arguments to git_config_add(): $@"
+
+    if [ "$(git config --get-all "$key")" = "$val" ]; then
+        SKIP=1 call "${c[@]}"
+        return 0
+    fi
+    call "${c[@]}"
+}
+
+git_config_add() {
+    local key="$1"
+    local val="$2"
+    local c=(git config --add "$key" "$val")
+
+    test "$#" == 2 || die "invalid arguments to git_config_add(): $@"
+
+    if git config --get-all "$key" | grep -qFx "$val"; then
+        SKIP=1 call "${c[@]}"
+        return 0
+    fi
+    call "${c[@]}"
+}
+
+CMD_NAME="$0"
+NO_TEST="$(get_bool NO_TEST 0)"
+
+for a; do
+    case "$a" in
+        --no-test)
+            NO_TEST=1
+            ;;
+        -h|--help)
+            usage
+            exit 0
+            ;;
+        *)
+            usage
+            die "Invalid argument \"$a\""
+            ;;
+    esac
+done
+
+case "$(git config --get-all remote.origin.url)" in
+    "https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git"| \
+    "git@gitlab.freedesktop.org:NetworkManager/NetworkManager.git")
+        ;;
+    *)
+        die "unexpected git repository. Expected that remote.origin.url is set to \"https://gitlab.freedesktop.org/NetworkManager/NetworkManager.git\""
+        ;;
+esac
+
+git_config_add blame.ignoreRevsFile '.git-blame-ignore-revs'
+git_config_add notes.displayref 'refs/notes/bugs'
+git_config_add remote.origin.fetch 'refs/notes/bugs:refs/notes/bugs'
+git_config_reset remote.origin.pushurl 'git@gitlab.freedesktop.org:NetworkManager/NetworkManager.git'
+
+if [ "$NO_TEST" != 1 ]; then
+    printf "Run with \"--no-test\" or see \"-h\"\n" >&2
+    printf "\n" >&2
+    printf "    \"%s\" --no-test\n" "$CMD_NAME" >&2
+fi