[PATCH] config option core.showroot to enable showing the diff of the root commit

@@ -110,6 +110,12 @@ core.legacyheaders::
 	database directly (where the "http://" and "rsync://" protocols
 	count as direct access).
 
+core.showroot::
+	If true, the initial commit will be shown as a big creation event.
+	This is equivalent to a diff against an empty tree.
+	Tools like gitlink:git-log[1] or gitlink:git-whatchanged[1], which
+	normally hide the root commit will now show it. True by default.
+
 alias.*::
 	Command aliases for the gitlink:git[1] command wrapper - e.g.
 	after defining "alias.last = cat-file commit HEAD", the invocation

@@ -72,6 +72,7 @@ int cmd_diff_tree(int argc, const char *
 	nr_sha1 = 0;
 	opt->abbrev = 0;
 	opt->diff = 1;
+	opt->show_root_diff = show_root_diff;
 	argc = setup_revisions(argc, argv, opt, NULL);
 
 	while (--argc > 0) {

@@ -53,6 +53,7 @@ int cmd_whatchanged(int argc, const char
 	rev.diff = 1;
 	rev.diffopt.recursive = 1;
 	rev.simplify_history = 0;
+	rev.show_root_diff = show_root_diff;
 	cmd_log_init(argc, argv, prefix, &rev);
 	if (!rev.diffopt.output_format)
 		rev.diffopt.output_format = DIFF_FORMAT_RAW;

@@ -72,6 +73,7 @@ int cmd_show(int argc, const char **argv
 	rev.always_show_header = 1;
 	rev.ignore_merges = 0;
 	rev.no_walk = 1;
+	rev.show_root_diff = show_root_diff;
 	cmd_log_init(argc, argv, prefix, &rev);
 	return cmd_log_walk(&rev);
 }

@@ -83,6 +85,7 @@ int cmd_log(int argc, const char **argv,
 	git_config(git_diff_ui_config);
 	init_revisions(&rev, prefix);
 	rev.always_show_header = 1;
+	rev.show_root_diff = show_root_diff;
 	cmd_log_init(argc, argv, prefix, &rev);
 	return cmd_log_walk(&rev);
 }

@@ -191,6 +191,7 @@ extern int warn_ambiguous_refs;
 extern int shared_repository;
 extern const char *apply_default_whitespace;
 extern int zlib_compression_level;
+extern int show_root_diff;
 
 #define GIT_REPO_VERSION 0
 extern int repository_format_version;

@@ -319,6 +319,11 @@ int git_default_config(const char *var,
 		return 0;
 	}
 
+	if (!strcmp(var, "core.showroot")) {
+		show_root_diff = git_config_bool(var, value);
+		return 0;
+	}
+
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
 }

@@ -24,6 +24,7 @@ const char *apply_default_whitespace;
 int zlib_compression_level = Z_DEFAULT_COMPRESSION;
 int pager_in_use;
 int pager_use_color = 1;
+int show_root_diff = 1;
 
 static const char *git_dir;
 static char *git_object_dir, *git_index_file, *git_refs_dir, *git_graft_file;