Fix repeated corruption of packed-refs

Signed-off-by: Davanum Srinivas <[email protected]>

artifacts/scripts/construct.sh

@@ -96,6 +96,30 @@ git config user.name "$GIT_COMMITTER_NAME"
 echo "Running garbage collection."
 git config gc.pruneExpire 3.days.ago
 git gc --auto
+
+# Remove corrupted lines in .git/packed-refs
+# Lines not starting with '^' caret are printed as-is. Lines
+# that do not start with a caret are printed ONLY if the previous
+# line did not start with a caret
+echo "Cleaning .git/packed-refs"
+cp .git/packed-refs .git/packed-refs.bak
+awk '
+NR == 1 {
+    prev_line_start_with_caret = 0
+}
+/^[^^]/ {
+    prev_line_start_with_caret = 0
+    print
+}
+/^\^/ {
+    if (!prev_line_start_with_caret) {
+        print
+    }
+    prev_line_start_with_caret = 1
+}
+' .git/packed-refs.bak > .git/packed-refs
+rm .git/packed-refs.bak
+
 echo "Fetching from origin."
 git fetch origin --no-tags --prune
 echo "Cleaning up checkout."