set-serial.sh: make more portable, faster and safer.

POSIX sh disallows dashes in function names, so rename the function to
set_serial_number.

Check for staged changes as well as non-staged once to see if the revision
has to be increased further.

Call set_serial_number just once in all cases, rather than calling it twice
if there are both new revisions and scheduled changes.

1 files changed, 5 insertions, 5 deletions

diff --git a/set-serial.sh b/set-serial.sh
index e6aa016..93a9140 100755
--- a/set-serial.sh
+++ b/set-serial.sh
@@ -2,7 +2,7 @@
 
 set -eu
 
-set-serial-number()
+set_serial_number()
 {
   sed >"$1.tmp" -e '/^$/q' "$1"
   echo >>"$1.tmp" "#serial $2"
@@ -15,11 +15,11 @@ for n in "$@"; do
   echo "$n ... "
   # Determine the number of revisions that have occurred to the macro.
   revision=$(git log --oneline -- "$n" | wc -l)
-  # Update the serial number in the m4 file.
-  set-serial-number "$n" "$revision"
   # Check whether git regards the file as "modified" now. If it does,
   # the serial number needs to be bumped one more time.
-  if ! git diff --quiet --exit-code -- "$n"; then
-    set-serial-number "$n" "$((revision + 1))"
+  if ! git diff --quiet --exit-code HEAD -- "$n"; then
+    revision="$((revision + 1))"
   fi
+  # Update the serial number in the m4 file.
+  set_serial_number "$n" "$revision"
 done