Merge branch 'jk/diff-submodule-diff-inline'

The "git diff --submodule={short,log}" mechanism has been enhanced
to allow "--submodule=diff" to show the patch between the submodule
commits bound to the superproject.

* jk/diff-submodule-diff-inline:
  diff: teach diff to display submodule difference with an inline diff
  submodule: refactor show_submodule_summary with helper function
  submodule: convert show_submodule_summary to use struct object_id *
  allow do_submodule_path to work even if submodule isn't checked out
  diff: prepare for additional submodule formats
  graph: add support for --line-prefix on all graph-aware output
  diff.c: remove output_prefix_length field
  cache: add empty_tree_oid object and helper function

1 files changed, 37 insertions, 17 deletions

diff --git a/diff.c b/diff.c
index 534c12e..b38d95e 100644
--- a/diff.c
+++ b/diff.c
@@ -18,6 +18,7 @@
 #include "ll-merge.h"
 #include "string-list.h"
 #include "argv-array.h"
+#include "graph.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
@@ -131,9 +132,11 @@ static int parse_dirstat_params(struct diff_options *options, const char *params
 static int parse_submodule_params(struct diff_options *options, const char *value)
 {
 	if (!strcmp(value, "log"))
-		DIFF_OPT_SET(options, SUBMODULE_LOG);
+		options->submodule_format = DIFF_SUBMODULE_LOG;
 	else if (!strcmp(value, "short"))
-		DIFF_OPT_CLR(options, SUBMODULE_LOG);
+		options->submodule_format = DIFF_SUBMODULE_SHORT;
+	else if (!strcmp(value, "diff"))
+		options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 	else
 		return -1;
 	return 0;
@@ -1625,7 +1628,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
 	 */
 
 	if (options->stat_width == -1)
-		width = term_columns() - options->output_prefix_length;
+		width = term_columns() - strlen(line_prefix);
 	else
 		width = options->stat_width ? options->stat_width : 80;
 	number_width = decimal_width(max_change) > number_width ?
@@ -2299,17 +2302,37 @@ static void builtin_diff(const char *name_a,
 	struct strbuf header = STRBUF_INIT;
 	const char *line_prefix = diff_line_prefix(o);
 
-	if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
-			(!one->mode || S_ISGITLINK(one->mode)) &&
-			(!two->mode || S_ISGITLINK(two->mode))) {
+	diff_set_mnemonic_prefix(o, "a/", "b/");
+	if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
+		a_prefix = o->b_prefix;
+		b_prefix = o->a_prefix;
+	} else {
+		a_prefix = o->a_prefix;
+		b_prefix = o->b_prefix;
+	}
+
+	if (o->submodule_format == DIFF_SUBMODULE_LOG &&
+	    (!one->mode || S_ISGITLINK(one->mode)) &&
+	    (!two->mode || S_ISGITLINK(two->mode))) {
 		const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
 		const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
 		show_submodule_summary(o->file, one->path ? one->path : two->path,
 				line_prefix,
-				one->oid.hash, two->oid.hash,
+				&one->oid, &two->oid,
 				two->dirty_submodule,
 				meta, del, add, reset);
 		return;
+	} else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
+		   (!one->mode || S_ISGITLINK(one->mode)) &&
+		   (!two->mode || S_ISGITLINK(two->mode))) {
+		const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
+		const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
+		show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
+				line_prefix,
+				&one->oid, &two->oid,
+				two->dirty_submodule,
+				meta, del, add, reset, o);
+		return;
 	}
 
 	if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
@@ -2317,15 +2340,6 @@ static void builtin_diff(const char *name_a,
 		textconv_two = get_textconv(two);
 	}
 
-	diff_set_mnemonic_prefix(o, "a/", "b/");
-	if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
-		a_prefix = o->b_prefix;
-		b_prefix = o->a_prefix;
-	} else {
-		a_prefix = o->a_prefix;
-		b_prefix = o->b_prefix;
-	}
-
 	/* Never use a non-valid filename anywhere if at all possible */
 	name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
 	name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
@@ -3915,7 +3929,7 @@ int diff_opt_parse(struct diff_options *options,
 		DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
 		handle_ignore_submodules_arg(options, arg);
 	} else if (!strcmp(arg, "--submodule"))
-		DIFF_OPT_SET(options, SUBMODULE_LOG);
+		options->submodule_format = DIFF_SUBMODULE_LOG;
 	else if (skip_prefix(arg, "--submodule=", &arg))
 		return parse_submodule_opt(options, arg);
 	else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
@@ -3966,6 +3980,12 @@ int diff_opt_parse(struct diff_options *options,
 		options->a_prefix = optarg;
 		return argcount;
 	}
+	else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
+		options->line_prefix = optarg;
+		options->line_prefix_length = strlen(options->line_prefix);
+		graph_setup_line_prefix(options);
+		return argcount;
+	}
 	else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
 		options->b_prefix = optarg;
 		return argcount;