[gnome-shell] ci: Wait for 'check-commit-log' before continuing

[Marge Bot <marge-bot src gnome org>]

commit e2945a525c92889c0e30abd7f770c992193e16e4
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Nov 6 18:07:07 2020 +0100

    ci: Wait for 'check-commit-log' before continuing
    
    The check-commit-log is quick, and to get a result early is helpful as
    one can then more quickly check for failures via the report provided via
    the JUnit report.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1491>

 .gitlab-ci.yml                 | 7 +++----
 .gitlab-ci/check-commit-log.sh | 4 ++--
 2 files changed, 5 insertions(+), 6 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 36dee4008c..78240e3920 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -25,8 +25,7 @@ check_commit_log:
         GIT_DEPTH: "100"
     script:
         - ./.gitlab-ci/check-commit-log.sh
-    only:
-        - merge_requests
+    <<: *only_default
     artifacts:
         expire_in: 1 week
         paths:
@@ -90,7 +89,7 @@ no_template_check:
 build:
     image: registry.gitlab.gnome.org/gnome/mutter/master:v4
     stage: build
-    needs: []
+    needs: ["check_commit_log"]
     before_script:
         - .gitlab-ci/checkout-mutter.sh
         - meson mutter mutter/build --prefix=/usr -Dtests=false
@@ -126,7 +125,7 @@ test:
 
 flatpak:
     stage: build
-    needs: []
+    needs: ["check_commit_log"]
     variables:
         SUBPROJECT: "subprojects/extensions-app"
         # Your manifest path
diff --git a/.gitlab-ci/check-commit-log.sh b/.gitlab-ci/check-commit-log.sh
index 7cc5b289ea..00fd893884 100755
--- a/.gitlab-ci/check-commit-log.sh
+++ b/.gitlab-ci/check-commit-log.sh
@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
 
 if [ -z "$CI_MERGE_REQUEST_TARGET_BRANCH_NAME" ]; then
-  echo Cannot review non-merge request
-  exit 1
+  echo This is not a merge request, skipping
+  exit 0
 fi
 
 git fetch $CI_MERGE_REQUEST_PROJECT_URL.git $CI_MERGE_REQUEST_TARGET_BRANCH_NAME