cmd/dist: improve isGitRepo to handle git "worktree"s

Simply checking the exit code of `git rev-parse --git-dir` should
suffice here, but that requires deviating from the infrastructure
provided by `run`, so I've left that for a future change.

Fixes #11211.

Change-Id: I7cbad86a8a06578f52f66f734f5447b597ddc962
Reviewed-on: https://go-review.googlesource.com/18213
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index 634c52c3b0fe554fab7ef18de9a626849ea81bb5..85cf3f913645c656911d24df145a21479b2d4a97 100644 (file)
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -322,18 +322,12 @@ func findgoversion() string {
 
 // isGitRepo reports whether the working directory is inside a Git repository.
 func isGitRepo() bool {
-       p := ".git"
-       for {
-               fi, err := os.Stat(p)
-               if os.IsNotExist(err) {
-                       p = filepath.Join("..", p)
-                       continue
-               }
-               if err != nil || !fi.IsDir() {
-                       return false
-               }
-               return true
-       }
+       // NB: simply checking the exit code of `git rev-parse --git-dir` would
+       // suffice here, but that requires deviating from the infrastructure
+       // provided by `run`.
+       gitDir := chomp(run(goroot, 0, "git", "rev-parse", "--git-dir"))
+       fi, err := os.Stat(gitDir)
+       return err == nil && fi.IsDir()
 }
 
 /*