resolve-undo: record resolved conflicts in a new index extension section
When resolving a conflict using "git add" to create a stage #0 entry, or
"git rm" to remove entries at higher stages, remove_index_entry_at()
function is eventually called to remove unmerged (i.e. higher stage)
entries from the index. Introduce a "resolve_undo_info" structure and
keep track of the removed cache entries, and save it in a new index
extension section in the index_state.
Operations like "read-tree -m", "merge", "checkout [-m] <branch>" and
"reset" are signs that recorded information in the index is no longer
necessary. The data is removed from the index extension when operations
start; they may leave conflicted entries in the index, and later user
actions like "git add" will record their conflicted states afresh.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Makefile b/Makefile
index 4a1e5bc..762898a 100644
--- a/Makefile
+++ b/Makefile
@@ -483,6 +483,7 @@
LIB_H += refs.h
LIB_H += remote.h
LIB_H += rerere.h
+LIB_H += resolve-undo.h
LIB_H += revision.h
LIB_H += run-command.h
LIB_H += sha1-lookup.h
@@ -578,6 +579,7 @@
LIB_OBJS += remote.o
LIB_OBJS += replace_object.o
LIB_OBJS += rerere.o
+LIB_OBJS += resolve-undo.o
LIB_OBJS += revision.o
LIB_OBJS += run-command.o
LIB_OBJS += server-info.o
