Merge branch 'tr/cache-tree' into maint-1.7.8

* tr/cache-tree:
t0090: be prepared that 'wc -l' writes leading blanks
reset: update cache-tree data when appropriate
commit: write cache-tree data when writing index anyway
Refactor cache_tree_update idiom from commit
Test the current state of the cache-tree optimization
Add test-scrap-cache-tree

diff --combined Makefile
index 3031be5ee63facad10da45271ab04a4be4f3bb68,b9400bcad31121f57cd421a1407322e7cab50ffc..6295422e10d0ee6440925569617e3d75142d702c
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -57,8 -57,8 +57,8 @@@ all:
  #
  # Define NO_STRLCPY if you don't have strlcpy.
  #
 -# Define NO_STRTOUMAX if you don't have strtoumax in the C library.
 -# If your compiler also does not support long long or does not have
 +# Define NO_STRTOUMAX if you don't have both strtoimax and strtoumax in the
 +# C library. If your compiler also does not support long long or does not have
  # strtoull, define NO_STRTOULL.
  #
  # Define NO_SETENV if you don't have setenv in the C library.
@@@ -435,6 -435,7 +435,7 @@@ TEST_PROGRAMS_NEED_X += test-ctyp
  TEST_PROGRAMS_NEED_X += test-date
  TEST_PROGRAMS_NEED_X += test-delta
  TEST_PROGRAMS_NEED_X += test-dump-cache-tree
+ TEST_PROGRAMS_NEED_X += test-scrap-cache-tree
  TEST_PROGRAMS_NEED_X += test-genrandom
  TEST_PROGRAMS_NEED_X += test-index-version
  TEST_PROGRAMS_NEED_X += test-line-buffer
@@@ -576,7 -577,6 +577,7 @@@ LIB_H += streaming.
  LIB_H += string-list.h
  LIB_H += submodule.h
  LIB_H += tag.h
 +LIB_H += thread-utils.h
  LIB_H += transport.h
  LIB_H += tree.h
  LIB_H += tree-walk.h
@@@ -1479,7 -1479,7 +1480,7 @@@ ifdef NO_STRLCP
  endif
  ifdef NO_STRTOUMAX
        COMPAT_CFLAGS += -DNO_STRTOUMAX
 -      COMPAT_OBJS += compat/strtoumax.o
 +      COMPAT_OBJS += compat/strtoumax.o compat/strtoimax.o
  endif
  ifdef NO_STRTOULL
        COMPAT_CFLAGS += -DNO_STRTOULL

diff --combined builtin/commit.c
index d8d6dd5eaaa5691a0b5059b9a43dd69761dcf72f,5125841f92bf709610a77c641afdccc4491b4440..d749cb112a0cff945528cbbfb303bc38db6b69e8
--- 1/builtin/commit.c
--- 2/builtin/commit.c
+++ b/builtin/commit.c
@@@ -103,7 -103,7 +103,7 @@@ static enum commit_whence whence
  static int use_editor = 1, include_status = 1;
  static int show_ignored_in_status;
  static const char *only_include_assumed;
 -static struct strbuf message;
 +static struct strbuf message = STRBUF_INIT;
  
  static int null_termination;
  static enum {
@@@ -138,7 -138,7 +138,7 @@@ static struct option builtin_commit_opt
        OPT_STRING('C', "reuse-message", &use_message, "commit", "reuse message from specified commit"),
        OPT_STRING(0, "fixup", &fixup_message, "commit", "use autosquash formatted message to fixup specified commit"),
        OPT_STRING(0, "squash", &squash_message, "commit", "use autosquash formatted message to squash specified commit"),
 -      OPT_BOOLEAN(0, "reset-author", &renew_authorship, "the commit is authored by me now (used with -C-c/--amend)"),
 +      OPT_BOOLEAN(0, "reset-author", &renew_authorship, "the commit is authored by me now (used with -C/-c/--amend)"),
        OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
        OPT_FILENAME('t', "template", &template_file, "use specified template file"),
        OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
@@@ -394,6 -394,7 +394,7 @@@ static char *prepare_index(int argc, co
                fd = hold_locked_index(&index_lock, 1);
                add_files_to_cache(also ? prefix : NULL, pathspec, 0);
                refresh_cache_or_die(refresh_flags);
+               update_main_cache_tree(1);
                if (write_cache(fd, active_cache, active_nr) ||
                    close_lock_file(&index_lock))
                        die(_("unable to write new_index file"));
@@@ -414,6 -415,7 +415,7 @@@
                fd = hold_locked_index(&index_lock, 1);
                refresh_cache_or_die(refresh_flags);
                if (active_cache_changed) {
+                       update_main_cache_tree(1);
                        if (write_cache(fd, active_cache, active_nr) ||
                            commit_locked_index(&index_lock))
                                die(_("unable to write new_index file"));
@@@ -862,10 -864,7 +864,7 @@@ static int prepare_to_commit(const cha
         */
        discard_cache();
        read_cache_from(index_file);
-       if (!active_cache_tree)
-               active_cache_tree = cache_tree();
-       if (cache_tree_update(active_cache_tree,
-                             active_cache, active_nr, 0, 0) < 0) {
+       if (update_main_cache_tree(0)) {
                error(_("Error building trees"));
                return 0;
        }