Only run code coverage CI on merge

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

.drone.yml

@@ -2213,6 +2213,7 @@ steps:
 - name: nodb-codecov
   image: nextcloudci/php7.1:php7.1-16
   commands:
+    - bash tests/drone-run-coverage.sh || exit 0
     - phpenmod xdebug
     - TEST_SELECTION=NODB ./autotest.sh sqlite
     - wget https://codecov.io/bash -O codecov.sh
@@ -2243,6 +2244,7 @@ steps:
 - name: db-codecov
   image: nextcloudci/php7.1:php7.1-16
   commands:
+    - bash tests/drone-run-coverage.sh || exit 0
     - phpenmod xdebug
     - TEST_SELECTION=QUICKDB ./autotest.sh sqlite
     - wget https://codecov.io/bash -O codecov.sh

tests/drone-run-coverage.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+echo "========================="
+echo "= List of changed files ="
+echo "========================="
+git diff --name-only origin/$DRONE_TARGET_BRANCH...$DRONE_COMMIT_SHA
+echo "========================="
+
+[[ $(git diff --name-only origin/$DRONE_TARGET_BRANCH...$DRONE_COMMIT_SHA | wc -l) -eq 0 ]] && echo "No files are modified => merge commit" && exit 0
+
+exit 1