ci: make grouping setup more generic

Make the grouping setup more generic by always calling `begin_group ()`
and `end_group ()` regardless of whether we have stubbed those functions
or not. This ensures we can more readily add support for additional CI
platforms.

Furthermore, the `group ()` function is made generic so that it is the
same for both GitHub Actions and for other platforms. There is a
semantic conflict here though: GitHub Actions used to call `set +x` in
`group ()` whereas the non-GitHub case unconditionally uses `set -x`.
The latter would get overriden if we kept the `set +x` in the generic
version of `group ()`. To resolve this conflict, we simply drop the `set
+x` in the generic variant of this function. As `begin_group ()` calls
`set -x` anyway this is not much of a change though, as the only
commands that aren't printed anymore now are the ones between the
beginning of `group ()` and the end of `begin_group ()`.

Last, this commit changes `end_group ()` to also accept a parameter that
indicates _which_ group should end. This will be required by a later
commit that introduces support for GitLab CI.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ci/lib.sh

@@ -14,36 +14,34 @@ then
 		need_to_end_group=
 		echo '::endgroup::' >&2
 	}
-	trap end_group EXIT
-
-	group () {
-		set +x
-		begin_group "$1"
-		shift
-		# work around `dash` not supporting `set -o pipefail`
-		(
-			"$@" 2>&1
-			echo $? >exit.status
-		) |
-		sed 's/^\(\([^ ]*\):\([0-9]*\):\([0-9]*:\) \)\(error\|warning\): /::\5 file=\2,line=\3::\1/'
-		res=$(cat exit.status)
-		rm exit.status
-		end_group
-		return $res
-	}
-
-	begin_group "CI setup"
 else
 	begin_group () { :; }
 	end_group () { :; }
 
-	group () {
-		shift
-		"$@"
-	}
 	set -x
 fi
 
+group () {
+	group="$1"
+	shift
+	begin_group "$group"
+
+	# work around `dash` not supporting `set -o pipefail`
+	(
+		"$@" 2>&1
+		echo $? >exit.status
+	) |
+	sed 's/^\(\([^ ]*\):\([0-9]*\):\([0-9]*:\) \)\(error\|warning\): /::\5 file=\2,line=\3::\1/'
+	res=$(cat exit.status)
+	rm exit.status
+
+	end_group "$group"
+	return $res
+}
+
+begin_group "CI setup"
+trap "end_group 'CI setup'" EXIT
+
 # Set 'exit on error' for all CI scripts to let the caller know that
 # something went wrong.
 #
@@ -285,5 +283,5 @@ esac
 
 MAKEFLAGS="$MAKEFLAGS CC=${CC:-cc}"
 
-end_group
+end_group "CI setup"
 set -x