Merge branch 'so/log-diff-merge'

"git log" learned a new "--diff-merges=<how>" option.

* so/log-diff-merge: (32 commits)
  t4013: add tests for --diff-merges=first-parent
  doc/git-show: include --diff-merges description
  doc/rev-list-options: document --first-parent changes merges format
  doc/diff-generate-patch: mention new --diff-merges option
  doc/git-log: describe new --diff-merges options
  diff-merges: add '--diff-merges=1' as synonym for 'first-parent'
  diff-merges: add old mnemonic counterparts to --diff-merges
  diff-merges: let new options enable diff without -p
  diff-merges: do not imply -p for new options
  diff-merges: implement new values for --diff-merges
  diff-merges: make -m/-c/--cc explicitly mutually exclusive
  diff-merges: refactor opt settings into separate functions
  diff-merges: get rid of now empty diff_merges_init_revs()
  diff-merges: group diff-merge flags next to each other inside 'rev_info'
  diff-merges: split 'ignore_merges' field
  diff-merges: fix -m to properly override -c/--cc
  t4013: add tests for -m failing to override -c/--cc
  t4013: support test_expect_failure through ':failure' magic
  diff-merges: revise revs->diff flag handling
  diff-merges: handle imply -p on -c/--cc logic for log.c
  ...

1 files changed, 7 insertions, 15 deletions

diff --git a/builtin/log.c b/builtin/log.c
index fd282def43..d0cbaaf68a 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -12,6 +12,7 @@
 #include "color.h"
 #include "commit.h"
 #include "diff.h"
+#include "diff-merges.h"
 #include "revision.h"
 #include "log-tree.h"
 #include "builtin.h"
@@ -607,15 +608,10 @@ static int show_tree_object(const struct object_id *oid,
 static void show_setup_revisions_tweak(struct rev_info *rev,
 				       struct setup_revision_opt *opt)
 {
-	if (rev->ignore_merges < 0) {
-		/* There was no "-m" variant on the command line */
-		rev->ignore_merges = 0;
-		if (!rev->first_parent_only && !rev->combine_merges) {
-			/* No "--first-parent", "-c", or "--cc" */
-			rev->combine_merges = 1;
-			rev->dense_combined_merges = 1;
-		}
-	}
+	if (rev->first_parent_only)
+		diff_merges_default_to_first_parent(rev);
+	else
+		diff_merges_default_to_dense_combined(rev);
 	if (!rev->diffopt.output_format)
 		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 }
@@ -736,12 +732,8 @@ static void log_setup_revisions_tweak(struct rev_info *rev,
 	    rev->prune_data.nr == 1)
 		rev->diffopt.flags.follow_renames = 1;
 
-	/* Turn --cc/-c into -p --cc/-c when -p was not given */
-	if (!rev->diffopt.output_format && rev->combine_merges)
-		rev->diffopt.output_format = DIFF_FORMAT_PATCH;
-
-	if (rev->first_parent_only && rev->ignore_merges < 0)
-		rev->ignore_merges = 0;
+	if (rev->first_parent_only)
+		diff_merges_default_to_first_parent(rev);
 }
 
 int cmd_log(int argc, const char **argv, const char *prefix)