git-sh-setup: Fix scripts whose PWD is a symlink into a git work-dir

diff --git a/git-sh-setup.sh b/git-sh-setup.sh
index 9cceb21a82881b5f12e85769fcbfeb2146631d3c..f07d96b9b5e3997b21736893be39ce91950f4878 100755 (executable)
--- a/git-sh-setup.sh
+++ b/git-sh-setup.sh
@@ -32,15 +32,16 @@ if test -n "$OPTIONS_SPEC"; then
                echo exit $?
        )"
 else
+       dashless=$(basename "$0" | sed -e 's/-/ /')
        usage() {
-               die "Usage: $0 $USAGE"
+               die "Usage: $dashless $USAGE"
        }
 
        if [ -z "$LONG_USAGE" ]
        then
-               LONG_USAGE="Usage: $0 $USAGE"
+               LONG_USAGE="Usage: $dashless $USAGE"
        else
-               LONG_USAGE="Usage: $0 $USAGE
+               LONG_USAGE="Usage: $dashless $USAGE
 
 $LONG_USAGE"
        fi
@@ -84,8 +85,27 @@ cd_to_toplevel () {
        cdup=$(git rev-parse --show-cdup)
        if test ! -z "$cdup"
        then
-               cd "$cdup" || {
-                       echo >&2 "Cannot chdir to $cdup, the toplevel of the working tree"
+               case "$cdup" in
+               /*)
+                       # Not quite the same as if we did "cd -P '$cdup'" when
+                       # $cdup contains ".." after symlink path components.
+                       # Don't fix that case at least until Git switches to
+                       # "cd -P" across the board.
+                       phys="$cdup"
+                       ;;
+               ..|../*|*/..|*/../*)
+                       # Interpret $cdup relative to the physical, not logical, cwd.
+                       # Probably /bin/pwd is more portable than passing -P to cd or pwd.
+                       phys="$(/bin/pwd)/$cdup"
+                       ;;
+               *)
+                       # There's no "..", so no need to make things absolute.
+                       phys="$cdup"
+                       ;;
+               esac
+
+               cd "$phys" || {
+                       echo >&2 "Cannot chdir to $phys, the toplevel of the working tree"
                        exit 1
                }
        fi