Merge branch 'jc/diff' into next

* jc/diff:
built-in diff: assorted updates.
built-in diff.

diff --combined Makefile
index 576067fafbd9fab97fa555ef7272d88e6a580892,277c1ac07932d9a00c58562533386e212c18b82a..895e6a1e4a7bc8a903b615f5852abbea862b403c
--- 1/Makefile
--- 2/Makefile
+++ b/Makefile
@@@ -204,7 -204,7 +204,7 @@@ DIFF_OBJS = 
        diffcore-delta.o log-tree.o
  
  LIB_OBJS = \
 -      blob.o commit.o connect.o csum-file.o \
 +      blob.o commit.o connect.o csum-file.o cache-tree.o \
        date.o diff-delta.o entry.o exec_cmd.o ident.o index.o \
        object.o pack-check.o patch-delta.o path.o pkt-line.o \
        quote.o read-cache.o refs.o run-command.o \
@@@ -214,7 -214,7 +214,7 @@@
        $(DIFF_OBJS)
  
  BUILTIN_OBJS = \
-       builtin-log.o builtin-help.o builtin-count.o
 -      builtin-log.o builtin-help.o builtin-diff.o
++      builtin-log.o builtin-help.o builtin-count.o builtin-diff.o
  
  GITLIBS = $(LIB_FILE) $(XDIFF_LIB)
  LIBS = $(GITLIBS) -lz
@@@ -609,10 -609,7 +609,10 @@@ test-date$X: test-date.c date.o ctype.
        $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) test-date.c date.o ctype.o
  
  test-delta$X: test-delta.c diff-delta.o patch-delta.o
 -      $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $^ -lz
 +      $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $^
 +
 +test-dump-cache-tree$X: dump-cache-tree.o $(GITLIBS)
 +      $(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
  
  check:
        for i in *.c; do sparse $(ALL_CFLAGS) $(SPARSE_FLAGS) $$i || exit; done

diff --combined builtin.h
index 15bb313ee26a21db06ca17fa09d4d31c27ecb07f,52ffa526f801af2a0be65c2722fc64b33577b60d..bf310dda9e2dbd45352ac1764bc911caaca549c3
--- 1/builtin.h
--- 2/builtin.h
+++ b/builtin.h
@@@ -19,7 -19,6 +19,8 @@@ extern int cmd_version(int argc, const 
  extern int cmd_whatchanged(int argc, const char **argv, char **envp);
  extern int cmd_show(int argc, const char **argv, char **envp);
  extern int cmd_log(int argc, const char **argv, char **envp);
 +extern int cmd_format_patch(int argc, const char **argv, char **envp);
 +extern int cmd_count_objects(int argc, const char **argv, char **envp);
+ extern int cmd_diff(int argc, const char **argv, char **envp);
  
  #endif

diff --combined git.c
index 6d030b01cc6b9a884b68573124e06787f7beb61c,ff9b87abbce78b639596bbf3f02b11a34174346b..a6ec3bcbe52b3f245f8304003eb1af39debec98f
--- 1/git.c
--- 2/git.c
+++ b/git.c
@@@ -46,8 -46,7 +46,9 @@@ static void handle_internal_command(in
                { "log", cmd_log },
                { "whatchanged", cmd_whatchanged },
                { "show", cmd_show },
 +              { "fmt-patch", cmd_format_patch },
 +              { "count-objects", cmd_count_objects },
+               { "diffn", cmd_diff },
        };
        int i;
  

diff --combined revision.c
index b6ed0149a5c3f34b4747bfcdedf4b2251b0a69ce,4381d455e4579fb2c6c598cee5e9252277590b28..3545df6119def92872080a3986e7d6ec3056e28d
--- 1/revision.c
--- 2/revision.c
+++ b/revision.c
@@@ -664,6 -664,7 +664,7 @@@ int setup_revisions(int argc, const cha
                        }
                        if (!strcmp(arg, "-c")) {
                                revs->diff = 1;
+                               revs->dense_combined_merges = 0;
                                revs->combine_merges = 1;
                                continue;
                        }
@@@ -740,11 -741,6 +741,11 @@@
                                include = get_reference(revs, next, sha1, flags);
                                if (!exclude || !include)
                                        die("Invalid revision range %s..%s", arg, next);
 +
 +                              if (!seen_dashdash) {
 +                                      *dotdot = '.';
 +                                      verify_non_filename(revs->prefix, arg);
 +                              }
                                add_pending_object(revs, exclude, this);
                                add_pending_object(revs, include, next);
                                continue;
@@@ -762,20 -758,13 +763,20 @@@
                        if (seen_dashdash || local_flags)
                                die("bad revision '%s'", arg);
  
 -                      /* If we didn't have a "--", all filenames must exist */
 +                      /* If we didn't have a "--":
 +                       * (1) all filenames must exist;
 +                       * (2) all rev-args must not be interpretable
 +                       *     as a valid filename.
 +                       * but the latter we have checked in the main loop.
 +                       */
                        for (j = i; j < argc; j++)
                                verify_filename(revs->prefix, argv[j]);
  
                        revs->prune_data = get_pathspec(revs->prefix, argv + i);
                        break;
                }
 +              if (!seen_dashdash)
 +                      verify_non_filename(revs->prefix, arg);
                object = get_reference(revs, arg, sha1, flags ^ local_flags);
                add_pending_object(revs, object, arg);
        }