git_command: Return None from GetEventTargetPath() if set to empty string

If trace2.eventTarget was set to the empty string,
match git behavior and don't write a trace.

Bug: 319673783
Change-Id: I02b3884ad97551f8a9d7363c2cbe6b0adee6f73e
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/410518
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
Tested-by: Peter Collingbourne <pcc@google.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/git_command.py b/git_command.py
index 3c3869a2..09ed1a79 100644
--- a/git_command.py
+++ b/git_command.py
@@ -135,6 +135,8 @@ def GetEventTargetPath():
     if retval == 0:
         # Strip trailing carriage-return in path.
         path = p.stdout.rstrip("\n")
+        if path == "":
+            return None
     elif retval != 1:
         # `git config --get` is documented to produce an exit status of `1`
         # if the requested variable is not present in the configuration.