ci: tracie dashboard URLs only in the failure after the testcase

When adding the direct link to the diff page in the resulting
JUnit XML file we were not correctly skipping the first line from the
matching range.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4261
Fixes: 27f8c46648 ("ci: recover tracie dashboard URLs for failing traces")
Signed-off-by: Andres Gomez <agomez@igalia.com>
Acked-by: Juan A. Suarez <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8939>

.gitlab-ci/piglit/run.sh

@@ -173,7 +173,12 @@ replay_minio_upload_images() {
             __PIGLIT_TESTCASE_CLASSNAME="piglit\.trace\.$PIGLIT_REPLAY_DEVICE_NAME\.$(dirname $__TRACE | sed 's%/%\\.%g;s@%@\\%@')"
             __PIGLIT_TESTCASE_NAME="$(basename $__TRACE | sed 's%\.%_%g;s@%@\\%@')"
             __DASHBOARD_URL="https://tracie.freedesktop.org/dashboard/imagediff/${CI_PROJECT_PATH}/${CI_JOB_ID}/${__TRACE}"
-            sed '\%<testcase classname="'"${__PIGLIT_TESTCASE_CLASSNAME}"'" name="'"${__PIGLIT_TESTCASE_NAME}"'" status="fail"%,\%</system-out><failure type="fail"/></testcase>%{s%</system-out><failure type="fail"/></testcase>%</system-out><failure type="fail">To view the image differences visit: '"${__DASHBOARD_URL}"'</failure></testcase>%}' \
+            __START_TEST_PATTERN='<testcase classname="'"${__PIGLIT_TESTCASE_CLASSNAME}"'" name="'"${__PIGLIT_TESTCASE_NAME}"'" status="fail"'
+            __REPLACE_TEST_PATTERN='</system-out><failure type="fail"/></testcase>'
+            # Replace in the range between __START_TEST_PATTERN and
+            # __REPLACE_TEST_PATTERN leaving __START_TEST_PATTERN out
+            # from the substitution
+            sed '\%'"${__START_TEST_PATTERN}"'%,\%'"${__REPLACE_TEST_PATTERN}"'%{\%'"${__START_TEST_PATTERN}"'%b;s%'"${__REPLACE_TEST_PATTERN}"'%</system-out><failure type="fail">To view the image differences visit: '"${__DASHBOARD_URL}"'</failure></testcase>%}' \
                 -i "$RESULTS"/junit.xml
         fi