Add an option not to use link(src, dest) && unlink(src) when that is unreliable

diff --git a/git-repack.sh b/git-repack.sh
index 4d313d136e64678b99179b2e1dce7a1beaa36d04..0868734723b3c96144bfa9360a9e19ebae1995f7 100755 (executable)
--- a/git-repack.sh
+++ b/git-repack.sh
@@ -60,6 +60,7 @@ case ",$all_into_one," in
        args='--unpacked --incremental'
        ;;
 ,t,)
+       args= existing=
        if [ -d "$PACKDIR" ]; then
                for e in `cd "$PACKDIR" && find . -type f -name '*.pack' \
                        | sed -e 's/^\.\///' -e 's/\.pack$//'`
@@ -67,11 +68,11 @@ case ",$all_into_one," in
                        if [ -e "$PACKDIR/$e.keep" ]; then
                                : keep
                        else
-                               args="$args --unpacked=$e.pack"
                                existing="$existing $e"
                        fi
                done
-               if test -n "$args" -a -n "$unpack_unreachable"
+               if test -n "$existing" -a -n "$unpack_unreachable" -a \
+                       -n "$remove_redundant"
                then
                        args="$args $unpack_unreachable"
                fi
@@ -87,32 +88,79 @@ if [ -z "$names" ]; then
                echo Nothing new to pack.
        fi
 fi
-for name in $names ; do
-       fullbases="$fullbases pack-$name"
-       chmod a-w "$PACKTMP-$name.pack"
-       chmod a-w "$PACKTMP-$name.idx"
-       mkdir -p "$PACKDIR" || exit
 
+# Ok we have prepared all new packfiles.
+mkdir -p "$PACKDIR" || exit
+
+# First see if there are packs of the same name and if so
+# if we can move them out of the way (this can happen if we
+# repacked immediately after packing fully.
+rollback=
+failed=
+for name in $names
+do
        for sfx in pack idx
        do
-               if test -f "$PACKDIR/pack-$name.$sfx"
-               then
-                       mv -f "$PACKDIR/pack-$name.$sfx" \
-                               "$PACKDIR/old-pack-$name.$sfx"
-               fi
-       done &&
+               file=pack-$name.$sfx
+               test -f "$PACKDIR/$file" || continue
+               rm -f "$PACKDIR/old-$file" &&
+               mv "$PACKDIR/$file" "$PACKDIR/old-$file" || {
+                       failed=t
+                       break
+               }
+               rollback="$rollback $file"
+       done
+       test -z "$failed" || break
+done
+
+# If renaming failed for any of them, roll the ones we have
+# already renamed back to their original names.
+if test -n "$failed"
+then
+       rollback_failure=
+       for file in $rollback
+       do
+               mv "$PACKDIR/old-$file" "$PACKDIR/$file" ||
+               rollback_failure="$rollback_failure $file"
+       done
+       if test -n "$rollback_failure"
+       then
+               echo >&2 "WARNING: Some packs in use have been renamed by"
+               echo >&2 "WARNING: prefixing old- to their name, in order to"
+               echo >&2 "WARNING: replace them with the new version of the"
+               echo >&2 "WARNING: file.  But the operation failed, and"
+               echo >&2 "WARNING: attempt to rename them back to their"
+               echo >&2 "WARNING: original names also failed."
+               echo >&2 "WARNING: Please rename them in $PACKDIR manually:"
+               for file in $rollback_failure
+               do
+                       echo >&2 "WARNING:   old-$file -> $file"
+               done
+       fi
+       exit 1
+fi
+
+# Now the ones with the same name are out of the way...
+fullbases=
+for name in $names
+do
+       fullbases="$fullbases pack-$name"
+       chmod a-w "$PACKTMP-$name.pack"
+       chmod a-w "$PACKTMP-$name.idx"
        mv -f "$PACKTMP-$name.pack" "$PACKDIR/pack-$name.pack" &&
-       mv -f "$PACKTMP-$name.idx"  "$PACKDIR/pack-$name.idx" &&
-       test -f "$PACKDIR/pack-$name.pack" &&
-       test -f "$PACKDIR/pack-$name.idx" || {
-               echo >&2 "Couldn't replace the existing pack with updated one."
-               echo >&2 "The original set of packs have been saved as"
-               echo >&2 "old-pack-$name.{pack,idx} in $PACKDIR."
-               exit 1
-       }
-       rm -f "$PACKDIR/old-pack-$name.pack" "$PACKDIR/old-pack-$name.idx"
+       mv -f "$PACKTMP-$name.idx"  "$PACKDIR/pack-$name.idx" ||
+       exit
+done
+
+# Remove the "old-" files
+for name in $names
+do
+       rm -f "$PACKDIR/old-pack-$name.idx"
+       rm -f "$PACKDIR/old-pack-$name.pack"
 done
 
+# End of pack replacement.
+
 if test "$remove_redundant" = t
 then
        # We know $existing are all redundant.
@@ -133,5 +181,5 @@ fi
 
 case "$no_update_info" in
 t) : ;;
-*) git-update-server-info ;;
+*) git update-server-info ;;
 esac