This is a straight backport of
https://gcc.gnu.org/ml/gcc-patches/2018-04/msg01352.html. Without this
contrib/gcc_update fails if run from a worktree, while git pull works
just fine.
Pushed to the gcc-8 branch.
diff --git a/contrib/ChangeLog b/contrib/ChangeLog
index 039dc251ebb..47ac7c47dcc 100644
--- a/contrib/ChangeLog
+++ b/contrib/ChangeLog
@@ -1,3 +1,10 @@
+2020-01-15 Richard Earnshaw <rearn...@arm.com>
+
+ Backport:
+ 2018-05-01 Jim Wilson <j...@sifive.com>
+
+ * gcc_update: Check for .git as a file.
+
2019-08-16 Uros Bizjak <ubiz...@gmail.com>
* test_summary: Do not escape "=".
diff --git a/contrib/gcc_update b/contrib/gcc_update
index a33bb543902..c9c71548f53 100755
--- a/contrib/gcc_update
+++ b/contrib/gcc_update
@@ -286,7 +286,7 @@ p
esac
# Check for known version control systems.
-if [ -d .git ]; then
+if [ -d .git ] || [ -f .git ]; then
GCC_GIT=${GCC_GIT-${GIT-git}}
vcs_type="git"
elif [ -d .hg ]; then
