ce_smudge_racily_clean_entry: explain why it works.

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index dbb98842bf6327210c604ae65a128cdfc785b32c..1e638e493d51c9216e3d2e93aad5657cdf9793b4 100755 (executable)
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -1,10 +1,9 @@
 #!/bin/sh
 #
-# Set up GIT_DIR and GIT_OBJECT_DIRECTORY
-# and return true if everything looks ok
-#
-: ${GIT_DIR=.git}
-: ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
+# This is included in commands that either have to be run from the toplevel
+# of the repository, or with GIT_DIR environment variable properly.
+# If the GIT_DIR does not look like the right correct git-repository,
+# it dies.
 
 # Having this variable in your environment would break scripts because
 # you would cause "cd" to be be taken to unexpected places.  If you
@@ -17,9 +16,32 @@ die() {
        exit 1
 }
 
-case "$(GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD 2>/dev/null)" in
-refs/*)        : ;;
-*)     false ;;
-esac &&
-[ -d "$GIT_DIR/refs" ] &&
-[ -d "$GIT_OBJECT_DIRECTORY/" ]
+usage() {
+       die "Usage: $0 $USAGE"
+}
+
+if [ -z "$LONG_USAGE" ]
+then
+       LONG_USAGE="Usage: $0 $USAGE"
+else
+       LONG_USAGE="Usage: $0 $USAGE
+
+$LONG_USAGE"
+fi
+
+case "$1" in
+       --h|--he|--hel|--help)
+       echo "$LONG_USAGE"
+       exit
+esac
+
+if [ -z "$SUBDIRECTORY_OK" ]
+then
+       : ${GIT_DIR=.git}
+       : ${GIT_OBJECT_DIRECTORY="$GIT_DIR/objects"}
+
+       # Make sure we are in a valid repository of a vintage we understand.
+       GIT_DIR="$GIT_DIR" git-var GIT_AUTHOR_IDENT >/dev/null || exit
+else
+       GIT_DIR=$(git-rev-parse --git-dir) || exit
+fi