git-p4: Unset P4DIFF environment variable when using 'p4 -du diff'

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index 5aa62dda15d1c24d0b01845ded4c8bc15e98bf8a..a44b1c74a38d6310d7a1bde969cbbcb51f977188 100755 (executable)
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -18,7 +18,8 @@ die() {
 
 if test -n "$OPTIONS_SPEC"; then
        usage() {
-               exec "$0" -h
+               "$0" -h
+               exit 1
        }
 
        parseopt_extra=
@@ -118,30 +119,26 @@ get_author_ident_from_commit () {
        }
        '
        encoding=$(git config i18n.commitencoding || echo UTF-8)
-       git show -s --pretty=raw --encoding="$encoding" "$1" |
+       git show -s --pretty=raw --encoding="$encoding" "$1" -- |
        LANG=C LC_ALL=C sed -ne "$pick_author_script"
 }
 
-# Make sure we are in a valid repository of a vintage we understand.
-if [ -z "$SUBDIRECTORY_OK" ]
+# Make sure we are in a valid repository of a vintage we understand,
+# if we require to be in a git repository.
+if test -z "$NONGIT_OK"
 then
-       : ${GIT_DIR=.git}
-       test -z "$(git rev-parse --show-cdup)" || {
-               exit=$?
-               echo >&2 "You need to run this command from the toplevel of the working tree."
-               exit $exit
-       }
-else
-       GIT_DIR=$(git rev-parse --git-dir) || {
-           exit=$?
-           echo >&2 "Failed to find a valid git directory."
-           exit $exit
+       GIT_DIR=$(git rev-parse --git-dir) || exit
+       if [ -z "$SUBDIRECTORY_OK" ]
+       then
+               test -z "$(git rev-parse --show-cdup)" || {
+                       exit=$?
+                       echo >&2 "You need to run this command from the toplevel of the working tree."
+                       exit $exit
+               }
+       fi
+       test -n "$GIT_DIR" && GIT_DIR=$(cd "$GIT_DIR" && pwd) || {
+               echo >&2 "Unable to determine absolute path of git directory"
+               exit 1
        }
+       : ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
 fi
-
-test -n "$GIT_DIR" && GIT_DIR=$(cd "$GIT_DIR" && pwd) || {
-    echo >&2 "Unable to determine absolute path of git directory"
-    exit 1
-}
-
-: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}