27 files changed, 1105 insertions, 48 deletions

diff --git a/.gitignore b/.gitignore
index 1dbeb668db..bf66648e2c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,7 @@
 /git-cherry-pick
 /git-clean
 /git-clone
+/git-column
 /git-commit
 /git-commit-tree
 /git-config
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 355ee53652..915cb5a547 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -856,6 +856,44 @@ color.ui::
 	`never` if you prefer git commands not to use color unless enabled
 	explicitly with some other configuration or the `--color` option.
 
+column.ui::
+	Specify whether supported commands should output in columns.
+	This variable consists of a list of tokens separated by spaces
+	or commas:
++
+--
+`always`;;
+	always show in columns
+`never`;;
+	never show in columns
+`auto`;;
+	show in columns if the output is to the terminal
+`column`;;
+	fill columns before rows (default)
+`row`;;
+	fill rows before columns
+`plain`;;
+	show in one column
+`dense`;;
+	make unequal size columns to utilize more space
+`nodense`;;
+	make equal size columns
+--
++
+	This option defaults to 'never'.
+
+column.branch::
+	Specify whether to output branch listing in `git branch` in columns.
+	See `column.ui` for details.
+
+column.status::
+	Specify whether to output untracked files in `git status` in columns.
+	See `column.ui` for details.
+
+column.tag::
+	Specify whether to output tag listing in `git tag` in columns.
+	See `column.ui` for details.
+
 commit.status::
 	A boolean to enable/disable inclusion of status information in the
 	commit message template when using an editor to prepare the commit
diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index e71370d6b4..47235bea04 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -10,6 +10,7 @@ SYNOPSIS
 [verse]
 'git branch' [--color[=<when>] | --no-color] [-r | -a]
 	[--list] [-v [--abbrev=<length> | --no-abbrev]]
+	[--column[=<options>] | --no-column]
 	[(--merged | --no-merged | --contains) [<commit>]] [<pattern>...]
 'git branch' [--set-upstream | --track | --no-track] [-l] [-f] <branchname> [<start-point>]
 'git branch' (-m | -M) [<oldbranch>] <newbranch>
@@ -107,6 +108,14 @@ OPTIONS
 	default to color output.
 	Same as `--color=never`.
 
+--column[=<options>]::
+--no-column::
+	Display branch listing in columns. See configuration variable
+	column.branch for option syntax.`--column` and `--no-column`
+	without options are equivalent to 'always' and 'never' respectively.
++
+This option is only applicable in non-verbose mode.
+
 -r::
 --remotes::
 	List or delete (if used with -d) the remote-tracking branches.
diff --git a/Documentation/git-column.txt b/Documentation/git-column.txt
new file mode 100644
index 0000000000..9be16eea0e
--- /dev/null
+++ b/Documentation/git-column.txt
@@ -0,0 +1,53 @@
+git-column(1)
+=============
+
+NAME
+----
+git-column - Display data in columns
+
+SYNOPSIS
+--------
+[verse]
+'git column' [--command=<name>] [--[raw-]mode=<mode>] [--width=<width>]
+	     [--indent=<string>] [--nl=<string>] [--pading=<n>]
+
+DESCRIPTION
+-----------
+This command formats its input into multiple columns.
+
+OPTIONS
+-------
+--command=<name>::
+	Look up layout mode using configuration variable column.<name> and
+	column.ui.
+
+--mode=<mode>::
+	Specify layout mode. See configuration variable column.ui for option
+	syntax.
+
+--raw-mode=<n>::
+	Same as --mode but take mode encoded as a number. This is mainly used
+	by other commands that have already parsed layout mode.
+
+--width=<width>::
+	Specify the terminal width. By default 'git column' will detect the
+	terminal width, or fall back to 80 if it is unable to do so.
+
+--indent=<string>::
+	String to be printed at the beginning of each line.
+
+--nl=<N>::
+	String to be printed at the end of each line,
+	including newline character.
+
+--padding=<N>::
+	The number of spaces between columns. One space by default.
+
+
+Author
+------
+Written by Nguyen Thai Ngoc Duy <pclouds@gmail.com>
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Documentation/git-status.txt b/Documentation/git-status.txt
index a29aae60cd..2883a285ba 100644
--- a/Documentation/git-status.txt
+++ b/Documentation/git-status.txt
@@ -77,6 +77,13 @@ configuration variable documented in linkgit:git-config[1].
 	Terminate entries with NUL, instead of LF.  This implies
 	the `--porcelain` output format if no other format is given.
 
+--column[=<options>]::
+--no-column::
+	Display untracked files in columns. See configuration variable
+	column.status for option syntax.`--column` and `--no-column`
+	without options are equivalent to 'always' and 'never'
+	respectively.
+
 
 OUTPUT
 ------
diff --git a/Documentation/git-tag.txt b/Documentation/git-tag.txt
index 8d32b9a814..e36a7c3d1e 100644
--- a/Documentation/git-tag.txt
+++ b/Documentation/git-tag.txt
@@ -13,6 +13,7 @@ SYNOPSIS
 	<tagname> [<commit> | <object>]
 'git tag' -d <tagname>...
 'git tag' [-n[<num>]] -l [--contains <commit>] [--points-at <object>]
+	[--column[=<options>] | --no-column] [<pattern>...]
 	[<pattern>...]
 'git tag' -v <tagname>...
 
@@ -84,6 +85,14 @@ OPTIONS
 	using fnmatch(3)).  Multiple patterns may be given; if any of
 	them matches, the tag is shown.
 
+--column[=<options>]::
+--no-column::
+	Display tag listing in columns. See configuration variable
+	column.tag for option syntax.`--column` and `--no-column`
+	without options are equivalent to 'always' and 'never' respectively.
++
+This option is only applicable when listing tags without annotation lines.
+
 --contains <commit>::
 	Only list tags which contain the specified commit.
 
diff --git a/Makefile b/Makefile
index bdf2a578df..ac40e24625 100644
--- a/Makefile
+++ b/Makefile
@@ -688,6 +688,7 @@ LIB_OBJS += bulk-checkin.o
 LIB_OBJS += bundle.o
 LIB_OBJS += cache-tree.o
 LIB_OBJS += color.o
+LIB_OBJS += column.o
 LIB_OBJS += combine-diff.o
 LIB_OBJS += commit.o
 LIB_OBJS += compat/obstack.o
@@ -818,6 +819,7 @@ BUILTIN_OBJS += builtin/checkout-index.o
 BUILTIN_OBJS += builtin/checkout.o
 BUILTIN_OBJS += builtin/clean.o
 BUILTIN_OBJS += builtin/clone.o
+BUILTIN_OBJS += builtin/column.o
 BUILTIN_OBJS += builtin/commit-tree.o
 BUILTIN_OBJS += builtin/commit.o
 BUILTIN_OBJS += builtin/config.o
@@ -2224,6 +2226,7 @@ builtin/prune.o builtin/reflog.o reachable.o: reachable.h
 builtin/commit.o builtin/revert.o wt-status.o: wt-status.h
 builtin/tar-tree.o archive-tar.o: tar.h
 connect.o transport.o url.o http-backend.o: url.h
+builtin/branch.o builtin/commit.o builtin/tag.o column.o help.o pager.o: column.h
 http-fetch.o http-walker.o remote-curl.o transport.o walker.o: walker.h
 http.o http-walker.o http-push.o http-fetch.o remote-curl.o: http.h url.h
 
diff --git a/builtin.h b/builtin.h
index 857b9c8aa8..338f540e39 100644
--- a/builtin.h
+++ b/builtin.h
@@ -61,6 +61,7 @@ extern int cmd_cherry(int argc, const char **argv, const char *prefix);
 extern int cmd_cherry_pick(int argc, const char **argv, const char *prefix);
 extern int cmd_clone(int argc, const char **argv, const char *prefix);
 extern int cmd_clean(int argc, const char **argv, const char *prefix);
+extern int cmd_column(int argc, const char **argv, const char *prefix);
 extern int cmd_commit(int argc, const char **argv, const char *prefix);
 extern int cmd_commit_tree(int argc, const char **argv, const char *prefix);
 extern int cmd_config(int argc, const char **argv, const char *prefix);
diff --git a/builtin/branch.c b/builtin/branch.c
index f12b626a0e..d51648fee4 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -15,6 +15,8 @@
 #include "branch.h"
 #include "diff.h"
 #include "revision.h"
+#include "string-list.h"
+#include "column.h"
 
 static const char * const builtin_branch_usage[] = {
 	"git branch [options] [-r | -a] [--merged | --no-merged]",
@@ -53,6 +55,9 @@ static enum merge_filter {
 } merge_filter;
 static unsigned char merge_filter_ref[20];
 
+static struct string_list output = STRING_LIST_INIT_DUP;
+static unsigned int colopts;
+
 static int parse_branch_color_slot(const char *var, int ofs)
 {
 	if (!strcasecmp(var+ofs, "plain"))
@@ -70,6 +75,8 @@ static int parse_branch_color_slot(const char *var, int ofs)
 
 static int git_branch_config(const char *var, const char *value, void *cb)
 {
+	if (!prefixcmp(var, "column."))
+		return git_column_config(var, value, "branch", &colopts);
 	if (!strcmp(var, "color.branch")) {
 		branch_use_color = git_config_colorbool(var, value);
 		return 0;
@@ -482,7 +489,12 @@ static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
 	else if (verbose)
 		/* " f7c0c00 [ahead 58, behind 197] vcs-svn: drop obj_pool.h" */
 		add_verbose_info(&out, item, verbose, abbrev);
-	printf("%s\n", out.buf);
+	if (column_active(colopts)) {
+		assert(!verbose && "--column and --verbose are incompatible");
+		string_list_append(&output, out.buf);
+	} else {
+		printf("%s\n", out.buf);
+	}
 	strbuf_release(&name);
 	strbuf_release(&out);
 }
@@ -741,6 +753,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 			PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG,
 			opt_parse_merge_filter, (intptr_t) "HEAD",
 		},
+		OPT_COLUMN(0, "column", &colopts, "list branches in columns"),
 		OPT_END(),
 	};
 
@@ -763,6 +776,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 	}
 	hashcpy(merge_filter_ref, head_sha1);
 
+
 	argc = parse_options(argc, argv, prefix, options, builtin_branch_usage,
 			     0);
 
@@ -774,12 +788,22 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 
 	if (abbrev == -1)
 		abbrev = DEFAULT_ABBREV;
+	finalize_colopts(&colopts, -1);
+	if (verbose) {
+		if (explicitly_enable_column(colopts))
+			die(_("--column and --verbose are incompatible"));
+		colopts = 0;
+	}
 
 	if (delete)
 		return delete_branches(argc, argv, delete > 1, kinds, quiet);
-	else if (list)
-		return print_ref_list(kinds, detached, verbose, abbrev,
-				      with_commit, argv);
+	else if (list) {
+		int ret = print_ref_list(kinds, detached, verbose, abbrev,
+					 with_commit, argv);
+		print_columns(&output, colopts, NULL);
+		string_list_clear(&output, 0);
+		return ret;
+	}
 	else if (edit_description) {
 		const char *branch_name;
 		struct strbuf branch_ref = STRBUF_INIT;
diff --git a/builtin/column.c b/builtin/column.c
new file mode 100644
index 0000000000..5ea798a7ca
--- /dev/null
+++ b/builtin/column.c
@@ -0,0 +1,59 @@
+#include "builtin.h"
+#include "cache.h"
+#include "strbuf.h"
+#include "parse-options.h"
+#include "string-list.h"
+#include "column.h"
+
+static const char * const builtin_column_usage[] = {
+	"git column [options]",
+	NULL
+};
+static unsigned int colopts;
+
+static int column_config(const char *var, const char *value, void *cb)
+{
+	return git_column_config(var, value, cb, &colopts);
+}
+
+int cmd_column(int argc, const char **argv, const char *prefix)
+{
+	struct string_list list = STRING_LIST_INIT_DUP;
+	struct strbuf sb = STRBUF_INIT;
+	struct column_options copts;
+	const char *command = NULL, *real_command = NULL;
+	struct option options[] = {
+		OPT_STRING(0, "command", &real_command, "name", "lookup config vars"),
+		OPT_COLUMN(0, "mode", &colopts, "layout to use"),
+		OPT_INTEGER(0, "raw-mode", &colopts, "layout to use"),
+		OPT_INTEGER(0, "width", &copts.width, "Maximum width"),
+		OPT_STRING(0, "indent", &copts.indent, "string", "Padding space on left border"),
+		OPT_INTEGER(0, "nl", &copts.nl, "Padding space on right border"),
+		OPT_INTEGER(0, "padding", &copts.padding, "Padding space between columns"),
+		OPT_END()
+	};
+
+	/* This one is special and must be the first one */
+	if (argc > 1 && !prefixcmp(argv[1], "--command=")) {
+		command = argv[1] + 10;
+		git_config(column_config, (void *)command);
+	} else
+		git_config(column_config, NULL);
+
+	memset(&copts, 0, sizeof(copts));
+	copts.width = term_columns();
+	copts.padding = 1;
+	argc = parse_options(argc, argv, "", options, builtin_column_usage, 0);
+	if (argc)
+		usage_with_options(builtin_column_usage, options);
+	if (real_command || command) {
+		if (!real_command || !command || strcmp(real_command, command))
+			die(_("--command must be the first argument"));
+	}
+	finalize_colopts(&colopts, -1);
+	while (!strbuf_getline(&sb, stdin, '\n'))
+		string_list_append(&list, sb.buf);
+
+	print_columns(&list, colopts, &copts);
+	return 0;
+}
diff --git a/builtin/commit.c b/builtin/commit.c
index 01780293aa..a876a73e6b 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -27,6 +27,7 @@
 #include "quote.h"
 #include "submodule.h"
 #include "gpg-interface.h"
+#include "column.h"
 
 static const char * const builtin_commit_usage[] = {
 	"git commit [options] [--] <filepattern>...",
@@ -88,6 +89,7 @@ static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
 static int no_post_rewrite, allow_empty_message;
 static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
 static char *sign_commit;
+static unsigned int colopts;
 
 /*
  * The default commit message cleanup mode will remove the lines
@@ -1173,6 +1175,8 @@ static int git_status_config(const char *k, const char *v, void *cb)
 {
 	struct wt_status *s = cb;
 
+	if (!prefixcmp(k, "column."))
+		return git_column_config(k, v, "status", &colopts);
 	if (!strcmp(k, "status.submodulesummary")) {
 		int is_bool;
 		s->submodule_summary = git_config_bool_or_int(k, v, &is_bool);
@@ -1238,6 +1242,7 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 		{ OPTION_STRING, 0, "ignore-submodules", &ignore_submodule_arg, "when",
 		  "ignore changes to submodules, optional when: all, dirty, untracked. (Default: all)",
 		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+		OPT_COLUMN(0, "column", &colopts, "list untracked files in columns"),
 		OPT_END(),
 	};
 
@@ -1251,6 +1256,8 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix,
 			     builtin_status_options,
 			     builtin_status_usage, 0);
+	finalize_colopts(&colopts, -1);
+	s.colopts = colopts;
 
 	if (null_termination && status_format == STATUS_FORMAT_LONG)
 		status_format = STATUS_FORMAT_PORCELAIN;
diff --git a/builtin/help.c b/builtin/help.c
index e63668ade4..43d3c84449 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -9,6 +9,7 @@
 #include "common-cmds.h"
 #include "parse-options.h"
 #include "run-command.h"
+#include "column.h"
 #include "help.h"
 
 static struct man_viewer_list {
@@ -30,6 +31,7 @@ enum help_format {
 };
 
 static int show_all = 0;
+static unsigned int colopts;
 static enum help_format help_format = HELP_FORMAT_NONE;
 static struct option builtin_help_options[] = {
 	OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
@@ -251,6 +253,8 @@ static int add_man_viewer_info(const char *var, const char *value)
 
 static int git_help_config(const char *var, const char *value, void *cb)
 {
+	if (!prefixcmp(var, "column."))
+		return git_column_config(var, value, "help", &colopts);
 	if (!strcmp(var, "help.format")) {
 		if (!value)
 			return config_error_nonbool(var);
@@ -424,8 +428,9 @@ int cmd_help(int argc, const char **argv, const char *prefix)
 	parsed_help_format = help_format;
 
 	if (show_all) {
+		git_config(git_help_config, NULL);
 		printf(_("usage: %s%s"), _(git_usage_string), "\n\n");
-		list_commands(&main_cmds, &other_cmds);
+		list_commands(colopts, &main_cmds, &other_cmds);
 		printf("%s\n", _(git_more_info_string));
 		return 0;
 	}
diff --git a/builtin/tag.c b/builtin/tag.c
index fe7e5e5b3d..4fb6bd7b3d 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -16,6 +16,7 @@
 #include "revision.h"
 #include "gpg-interface.h"
 #include "sha1-array.h"
+#include "column.h"
 
 static const char * const git_tag_usage[] = {
 	"git tag [-a|-s|-u <key-id>] [-f] [-m <msg>|-F <file>] <tagname> [<head>]",
@@ -33,6 +34,7 @@ struct tag_filter {
 };
 
 static struct sha1_array points_at;
+static unsigned int colopts;
 
 static int match_pattern(const char **patterns, const char *ref)
 {
@@ -263,6 +265,8 @@ static int git_tag_config(const char *var, const char *value, void *cb)
 	int status = git_gpg_config(var, value, cb);
 	if (status)
 		return status;
+	if (!prefixcmp(var, "column."))
+		return git_column_config(var, value, "tag", &colopts);
 	return git_default_config(var, value, cb);
 }
 
@@ -459,6 +463,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 		OPT_STRING('u', "local-user", &keyid, "key-id",
 					"use another key to sign the tag"),
 		OPT__FORCE(&force, "replace the tag if exists"),
+		OPT_COLUMN(0, "column", &colopts, "show tag list in columns"),
 
 		OPT_GROUP("Tag listing options"),
 		{
@@ -495,9 +500,25 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 
 	if (list + delete + verify > 1)
 		usage_with_options(git_tag_usage, options);
-	if (list)
-		return list_tags(argv, lines == -1 ? 0 : lines,
-				 with_commit);
+	finalize_colopts(&colopts, -1);
+	if (list && lines != -1) {
+		if (explicitly_enable_column(colopts))
+			die(_("--column and -n are incompatible"));
+		colopts = 0;
+	}
+	if (list) {
+		int ret;
+		if (column_active(colopts)) {
+			struct column_options copts;
+			memset(&copts, 0, sizeof(copts));
+			copts.padding = 2;
+			run_column_filter(colopts, &copts);
+		}
+		ret = list_tags(argv, lines == -1 ? 0 : lines, with_commit);
+		if (column_active(colopts))
+			stop_column_filter();
+		return ret;
+	}
 	if (lines != -1)
 		die(_("-n option is only allowed with -l."));
 	if (with_commit)
diff --git a/column.c b/column.c
new file mode 100644
index 0000000000..9367ba5db5
--- /dev/null
+++ b/column.c
@@ -0,0 +1,434 @@
+#include "cache.h"
+#include "column.h"
+#include "string-list.h"
+#include "parse-options.h"
+#include "run-command.h"
+#include "utf8.h"
+
+#define XY2LINEAR(d, x, y) (COL_LAYOUT((d)->colopts) == COL_COLUMN ? \
+			    (x) * (d)->rows + (y) : \
+			    (y) * (d)->cols + (x))
+
+struct column_data {
+	const struct string_list *list;
+	unsigned int colopts;
+	struct column_options opts;
+
+	int rows, cols;
+	int *len;		/* cell length */
+	int *width;	      /* index to the longest row in column */
+};
+
+/* return length of 's' in letters, ANSI escapes stripped */
+static int item_length(unsigned int colopts, const char *s)
+{
+	int len, i = 0;
+	struct strbuf str = STRBUF_INIT;
+
+	strbuf_addstr(&str, s);
+	while ((s = strstr(str.buf + i, "\033[")) != NULL) {
+		int len = strspn(s + 2, "0123456789;");
+		i = s - str.buf;
+		strbuf_remove(&str, i, len + 3); /* \033[<len><func char> */
+	}
+	len = utf8_strwidth(str.buf);
+	strbuf_release(&str);
+	return len;
+}
+
+/*
+ * Calculate cell width, rows and cols for a table of equal cells, given
+ * table width and how many spaces between cells.
+ */
+static void layout(struct column_data *data, int *width)
+{
+	int i;
+
+	*width = 0;
+	for (i = 0; i < data->list->nr; i++)
+		if (*width < data->len[i])
+			*width = data->len[i];
+
+	*width += data->opts.padding;
+
+	data->cols = (data->opts.width - strlen(data->opts.indent)) / *width;
+	if (data->cols == 0)
+		data->cols = 1;
+
+	data->rows = DIV_ROUND_UP(data->list->nr, data->cols);
+}
+
+static void compute_column_width(struct column_data *data)
+{
+	int i, x, y;
+	for (x = 0; x < data->cols; x++) {
+		data->width[x] = XY2LINEAR(data, x, 0);
+		for (y = 0; y < data->rows; y++) {
+			i = XY2LINEAR(data, x, y);
+			if (i < data->list->nr &&
+			    data->len[data->width[x]] < data->len[i])
+				data->width[x] = i;
+		}
+	}
+}
+
+/*
+ * Shrink all columns by shortening them one row each time (and adding
+ * more columns along the way). Hopefully the longest cell will be
+ * moved to the next column, column is shrunk so we have more space
+ * for new columns. The process ends when the whole thing no longer
+ * fits in data->total_width.
+ */
+static void shrink_columns(struct column_data *data)
+{
+	data->width = xrealloc(data->width,
+			       sizeof(*data->width) * data->cols);
+	while (data->rows > 1) {
+		int x, total_width, cols, rows;
+		rows = data->rows;
+		cols = data->cols;
+
+		data->rows--;
+		data->cols = DIV_ROUND_UP(data->list->nr, data->rows);
+		if (data->cols != cols)
+			data->width = xrealloc(data->width,
+					       sizeof(*data->width) * data->cols);
+		compute_column_width(data);
+
+		total_width = strlen(data->opts.indent);
+		for (x = 0; x < data->cols; x++) {
+			total_width += data->len[data->width[x]];
+			total_width += data->opts.padding;
+		}
+		if (total_width > data->opts.width) {
+			data->rows = rows;
+			data->cols = cols;
+			break;
+		}
+	}
+	compute_column_width(data);
+}
+
+/* Display without layout when not enabled */
+static void display_plain(const struct string_list *list,
+			  const char *indent, const char *nl)
+{
+	int i;
+
+	for (i = 0; i < list->nr; i++)
+		printf("%s%s%s", indent, list->items[i].string, nl);
+}
+
+/* Print a cell to stdout with all necessary leading/traling space */
+static int display_cell(struct column_data *data, int initial_width,
+			const char *empty_cell, int x, int y)
+{
+	int i, len, newline;
+
+	i = XY2LINEAR(data, x, y);
+	if (i >= data->list->nr)
+		return -1;
+
+	len = data->len[i];
+	if (data->width && data->len[data->width[x]] < initial_width) {
+		/*
+		 * empty_cell has initial_width chars, if real column
+		 * is narrower, increase len a bit so we fill less
+		 * space.
+		 */
+		len += initial_width - data->len[data->width[x]];
+		len -= data->opts.padding;
+	}
+
+	if (COL_LAYOUT(data->colopts) == COL_COLUMN)
+		newline = i + data->rows >= data->list->nr;
+	else
+		newline = x == data->cols - 1 || i == data->list->nr - 1;
+
+	printf("%s%s%s",
+	       x == 0 ? data->opts.indent : "",
+	       data->list->items[i].string,
+	       newline ? data->opts.nl : empty_cell + len);
+	return 0;
+}
+
+/* Display COL_COLUMN or COL_ROW */
+static void display_table(const struct string_list *list,
+			  unsigned int colopts,
+			  const struct column_options *opts)
+{
+	struct column_data data;
+	int x, y, i, initial_width;
+	char *empty_cell;
+
+	memset(&data, 0, sizeof(data));
+	data.list = list;
+	data.colopts = colopts;
+	data.opts = *opts;
+
+	data.len = xmalloc(sizeof(*data.len) * list->nr);
+	for (i = 0; i < list->nr; i++)
+		data.len[i] = item_length(colopts, list->items[i].string);
+
+	layout(&data, &initial_width);
+
+	if (colopts & COL_DENSE)
+		shrink_columns(&data);
+
+	empty_cell = xmalloc(initial_width + 1);
+	memset(empty_cell, ' ', initial_width);
+	empty_cell[initial_width] = '\0';
+	for (y = 0; y < data.rows; y++) {
+		for (x = 0; x < data.cols; x++)
+			if (display_cell(&data, initial_width, empty_cell, x, y))
+				break;
+	}
+
+	free(data.len);
+	free(data.width);
+	free(empty_cell);
+}
+
+void print_columns(const struct string_list *list, unsigned int colopts,
+		   const struct column_options *opts)
+{
+	struct column_options nopts;
+
+	if (!list->nr)
+		return;
+	assert((colopts & COL_ENABLE_MASK) != COL_AUTO);
+
+	memset(&nopts, 0, sizeof(nopts));
+	nopts.indent = opts && opts->indent ? opts->indent : "";
+	nopts.nl = opts && opts->nl ? opts->nl : "\n";
+	nopts.padding = opts ? opts->padding : 1;
+	nopts.width = opts && opts->width ? opts->width : term_columns() - 1;
+	if (!column_active(colopts)) {
+		display_plain(list, "", "\n");
+		return;
+	}
+	switch (COL_LAYOUT(colopts)) {
+	case COL_PLAIN:
+		display_plain(list, nopts.indent, nopts.nl);
+		break;
+	case COL_ROW:
+	case COL_COLUMN:
+		display_table(list, colopts, &nopts);
+		break;
+	default:
+		die("BUG: invalid layout mode %d", COL_LAYOUT(colopts));
+	}
+}
+
+int finalize_colopts(unsigned int *colopts, int stdout_is_tty)
+{
+	if ((*colopts & COL_ENABLE_MASK) == COL_AUTO) {
+		if (stdout_is_tty < 0)
+			stdout_is_tty = isatty(1);
+		*colopts &= ~COL_ENABLE_MASK;
+		if (stdout_is_tty)
+			*colopts |= COL_ENABLED;
+	}
+	return 0;
+}
+
+struct colopt {
+	const char *name;
+	unsigned int value;
+	unsigned int mask;
+};
+
+#define LAYOUT_SET 1
+#define ENABLE_SET 2
+
+static int parse_option(const char *arg, int len, unsigned int *colopts,
+			int *group_set)
+{
+	struct colopt opts[] = {
+		{ "always", COL_ENABLED,  COL_ENABLE_MASK },
+		{ "never",  COL_DISABLED, COL_ENABLE_MASK },
+		{ "auto",   COL_AUTO,     COL_ENABLE_MASK },
+		{ "plain",  COL_PLAIN,    COL_LAYOUT_MASK },
+		{ "column", COL_COLUMN,   COL_LAYOUT_MASK },
+		{ "row",    COL_ROW,      COL_LAYOUT_MASK },
+		{ "dense",  COL_DENSE,    0 },
+	};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(opts); i++) {
+		int set = 1, arg_len = len, name_len;
+		const char *arg_str = arg;
+
+		if (!opts[i].mask) {
+			if (arg_len > 2 && !strncmp(arg_str, "no", 2)) {
+				arg_str += 2;
+				arg_len -= 2;
+				set = 0;
+			}
+		}
+
+		name_len = strlen(opts[i].name);
+		if (arg_len != name_len ||
+		    strncmp(arg_str, opts[i].name, name_len))
+			continue;
+
+		switch (opts[i].mask) {
+		case COL_ENABLE_MASK:
+			*group_set |= ENABLE_SET;
+			break;
+		case COL_LAYOUT_MASK:
+			*group_set |= LAYOUT_SET;
+			break;
+		}
+
+		if (opts[i].mask)
+			*colopts = (*colopts & ~opts[i].mask) | opts[i].value;
+		else {
+			if (set)
+				*colopts |= opts[i].value;
+			else
+				*colopts &= ~opts[i].value;
+		}
+		return 0;
+	}
+
+	return error("unsupported option '%s'", arg);
+}
+
+static int parse_config(unsigned int *colopts, const char *value)
+{
+	const char *sep = " ,";
+	int group_set = 0;
+
+	while (*value) {
+		int len = strcspn(value, sep);
+		if (len) {
+			if (parse_option(value, len, colopts, &group_set))
+				return -1;
+
+			value += len;
+		}
+		value += strspn(value, sep);
+	}
+	/*
+	 * Setting layout implies "always" if neither always, never
+	 * nor auto is specified.
+	 *
+	 * Current value in COL_ENABLE_MASK is disregarded. This means if
+	 * you set column.ui = auto and pass --column=row, then "auto"
+	 * will become "always".
+	 */
+	if ((group_set & LAYOUT_SET) && !(group_set & ENABLE_SET))
+		*colopts = (*colopts & ~COL_ENABLE_MASK) | COL_ENABLED;
+	return 0;
+}
+
+static int column_config(const char *var, const char *value,
+			 const char *key, unsigned int *colopts)
+{
+	if (!value)
+		return config_error_nonbool(var);
+	if (parse_config(colopts, value))
+		return error("invalid column.%s mode %s", key, value);
+	return 0;
+}
+
+int git_column_config(const char *var, const char *value,
+		      const char *command, unsigned int *colopts)
+{
+	const char *it = skip_prefix(var, "column.");
+	if (!it)
+		return 0;
+
+	if (!strcmp(it, "ui"))
+		return column_config(var, value, "ui", colopts);
+
+	if (command && !strcmp(it, command))
+		return column_config(var, value, it, colopts);
+
+	return 0;
+}
+
+int parseopt_column_callback(const struct option *opt,
+			     const char *arg, int unset)
+{
+	unsigned int *colopts = opt->value;
+	*colopts |= COL_PARSEOPT;
+	*colopts &= ~COL_ENABLE_MASK;
+	if (unset)		/* --no-column == never */
+		return 0;
+	/* --column == always unless "arg" states otherwise */
+	*colopts |= COL_ENABLED;
+	if (arg)
+		return parse_config(colopts, arg);
+
+	return 0;
+}
+
+static int fd_out = -1;
+static struct child_process column_process;
+
+int run_column_filter(int colopts, const struct column_options *opts)
+{
+	const char *av[10];
+	int ret, ac = 0;
+	struct strbuf sb_colopt  = STRBUF_INIT;
+	struct strbuf sb_width   = STRBUF_INIT;
+	struct strbuf sb_padding = STRBUF_INIT;
+
+	if (fd_out != -1)
+		return -1;
+
+	av[ac++] = "column";
+	strbuf_addf(