Merge branch 'js/add-p-in-c'

The effort to move "git-add--interactive" to C continues.

* js/add-p-in-c:
  built-in add -p: show helpful hint when nothing can be staged
  built-in add -p: only show the applicable parts of the help text
  built-in add -p: implement the 'q' ("quit") command
  built-in add -p: implement the '/' ("search regex") command
  built-in add -p: implement the 'g' ("goto") command
  built-in add -p: implement hunk editing
  strbuf: add a helper function to call the editor "on an strbuf"
  built-in add -p: coalesce hunks after splitting them
  built-in add -p: implement the hunk splitting feature
  built-in add -p: show different prompts for mode changes and deletions
  built-in app -p: allow selecting a mode change as a "hunk"
  built-in add -p: handle deleted empty files
  built-in add -p: support multi-file diffs
  built-in add -p: offer a helpful error message when hunk navigation failed
  built-in add -p: color the prompt and the help text
  built-in add -p: adjust hunk headers as needed
  built-in add -p: show colored hunks by default
  built-in add -i: wire up the new C code for the `patch` command
  built-in add -i: start implementing the `patch` functionality in C

Makefile

@@ -825,6 +825,7 @@ LIB_H := $(sort $(patsubst ./%,%,$(shell git ls-files '*.h' ':!t/' ':!Documentat
 
 LIB_OBJS += abspath.o
 LIB_OBJS += add-interactive.o
+LIB_OBJS += add-patch.o
 LIB_OBJS += advice.o
 LIB_OBJS += alias.o
 LIB_OBJS += alloc.o

add-interactive.c

@@ -10,16 +10,6 @@
 #include "dir.h"
 #include "run-command.h"
 
-struct add_i_state {
-	struct repository *r;
-	int use_color;
-	char header_color[COLOR_MAXLEN];
-	char help_color[COLOR_MAXLEN];
-	char prompt_color[COLOR_MAXLEN];
-	char error_color[COLOR_MAXLEN];
-	char reset_color[COLOR_MAXLEN];
-};
-
 static void init_color(struct repository *r, struct add_i_state *s,
 		       const char *slot_name, char *dst,
 		       const char *default_color)
@@ -36,7 +26,7 @@ static void init_color(struct repository *r, struct add_i_state *s,
 	free(key);
 }
 
-static void init_add_i_state(struct add_i_state *s, struct repository *r)
+void init_add_i_state(struct add_i_state *s, struct repository *r)
 {
 	const char *value;
 
@@ -54,6 +44,14 @@ static void init_add_i_state(struct add_i_state *s, struct repository *r)
 	init_color(r, s, "prompt", s->prompt_color, GIT_COLOR_BOLD_BLUE);
 	init_color(r, s, "error", s->error_color, GIT_COLOR_BOLD_RED);
 	init_color(r, s, "reset", s->reset_color, GIT_COLOR_RESET);
+	init_color(r, s, "fraginfo", s->fraginfo_color,
+		   diff_get_color(s->use_color, DIFF_FRAGINFO));
+	init_color(r, s, "context", s->context_color,
+		diff_get_color(s->use_color, DIFF_CONTEXT));
+	init_color(r, s, "old", s->file_old_color,
+		diff_get_color(s->use_color, DIFF_FILE_OLD));
+	init_color(r, s, "new", s->file_new_color,
+		diff_get_color(s->use_color, DIFF_FILE_NEW));
 }
 
 /*
@@ -917,15 +915,18 @@ static int run_patch(struct add_i_state *s, const struct pathspec *ps,
 	count = list_and_choose(s, files, opts);
 	if (count >= 0) {
 		struct argv_array args = ARGV_ARRAY_INIT;
+		struct pathspec ps_selected = { 0 };
 
-		argv_array_pushl(&args, "git", "add--interactive", "--patch",
-				 "--", NULL);
 		for (i = 0; i < files->items.nr; i++)
 			if (files->selected[i])
 				argv_array_push(&args,
 						files->items.items[i].string);
-		res = run_command_v_opt(args.argv, 0);
+		parse_pathspec(&ps_selected,
+			       PATHSPEC_ALL_MAGIC & ~PATHSPEC_LITERAL,
+			       PATHSPEC_LITERAL_PATH, "", args.argv);
+		res = run_add_p(s->r, &ps_selected);
 		argv_array_clear(&args);
+		clear_pathspec(&ps_selected);
 	}
 
 	return res;

add-interactive.h

@@ -1,8 +1,27 @@
 #ifndef ADD_INTERACTIVE_H
 #define ADD_INTERACTIVE_H
 
+#include "color.h"
+
+struct add_i_state {
+	struct repository *r;
+	int use_color;
+	char header_color[COLOR_MAXLEN];
+	char help_color[COLOR_MAXLEN];
+	char prompt_color[COLOR_MAXLEN];
+	char error_color[COLOR_MAXLEN];
+	char reset_color[COLOR_MAXLEN];
+	char fraginfo_color[COLOR_MAXLEN];
+	char context_color[COLOR_MAXLEN];
+	char file_old_color[COLOR_MAXLEN];
+	char file_new_color[COLOR_MAXLEN];
+};
+
+void init_add_i_state(struct add_i_state *s, struct repository *r);
+
 struct repository;
 struct pathspec;
 int run_add_i(struct repository *r, const struct pathspec *ps);
+int run_add_p(struct repository *r, const struct pathspec *ps);
 
 #endif

builtin/add.c

@@ -191,12 +191,17 @@ int run_add_interactive(const char *revision, const char *patch_mode,
 	int use_builtin_add_i =
 		git_env_bool("GIT_TEST_ADD_I_USE_BUILTIN", -1);
 
-	if (!patch_mode) {
-		if (use_builtin_add_i < 0)
-			git_config_get_bool("add.interactive.usebuiltin",
-					    &use_builtin_add_i);
-		if (use_builtin_add_i == 1)
+	if (use_builtin_add_i < 0)
+		git_config_get_bool("add.interactive.usebuiltin",
+				    &use_builtin_add_i);
+
+	if (use_builtin_add_i == 1) {
+		if (!patch_mode)
 			return !!run_add_i(the_repository, pathspec);
+		if (strcmp(patch_mode, "--patch"))
+			die("'%s' not yet supported in the built-in add -p",
+			    patch_mode);
+		return !!run_add_p(the_repository, pathspec);
 	}
 
 	argv_array_push(&argv, "add--interactive");

strbuf.c

@@ -1125,3 +1125,31 @@ int strbuf_normalize_path(struct strbuf *src)
 	strbuf_release(&dst);
 	return 0;
 }
+
+int strbuf_edit_interactively(struct strbuf *buffer, const char *path,
+			      const char *const *env)
+{
+	char *path2 = NULL;
+	int fd, res = 0;
+
+	if (!is_absolute_path(path))
+		path = path2 = xstrdup(git_path("%s", path));
+
+	fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+	if (fd < 0)
+		res = error_errno(_("could not open '%s' for writing"), path);
+	else if (write_in_full(fd, buffer->buf, buffer->len) < 0) {
+		res = error_errno(_("could not write to '%s'"), path);
+		close(fd);
+	} else if (close(fd) < 0)
+		res = error_errno(_("could not close '%s'"), path);
+	else {
+		strbuf_reset(buffer);
+		if (launch_editor(path, buffer, env) < 0)
+			res = error_errno(_("could not edit '%s'"), path);
+		unlink(path);
+	}
+
+	free(path2);
+	return res;
+}

strbuf.h

@@ -621,6 +621,17 @@ int launch_editor(const char *path, struct strbuf *buffer,
 int launch_sequence_editor(const char *path, struct strbuf *buffer,
 			   const char *const *env);
 
+/*
+ * In contrast to `launch_editor()`, this function writes out the contents
+ * of the specified file first, then clears the `buffer`, then launches
+ * the editor and reads back in the file contents into the `buffer`.
+ * Finally, it deletes the temporary file.
+ *
+ * If `path` is relative, it refers to a file in the `.git` directory.
+ */
+int strbuf_edit_interactively(struct strbuf *buffer, const char *path,
+			      const char *const *env);
+
 void strbuf_add_lines(struct strbuf *sb,
 		      const char *prefix,
 		      const char *buf,

t/t3701-add-interactive.sh

@@ -413,6 +413,36 @@ test_expect_success 'split hunk setup' '
 	test_write_lines 10 15 20 21 22 23 24 30 40 50 60 >test
 '
 
+test_expect_success 'goto hunk' '
+	test_when_finished "git reset" &&
+	tr _ " " >expect <<-EOF &&
+	(2/2) Stage this hunk [y,n,q,a,d,K,g,/,e,?]? + 1:  -1,2 +1,3          +15
+	_ 2:  -2,4 +3,8          +21
+	go to which hunk? @@ -1,2 +1,3 @@
+	_10
+	+15
+	_20
+	(1/2) Stage this hunk [y,n,q,a,d,j,J,g,/,e,?]?_
+	EOF
+	test_write_lines s y g 1 | git add -p >actual &&
+	tail -n 7 <actual >actual.trimmed &&
+	test_cmp expect actual.trimmed
+'
+
+test_expect_success 'navigate to hunk via regex' '
+	test_when_finished "git reset" &&
+	tr _ " " >expect <<-EOF &&
+	(2/2) Stage this hunk [y,n,q,a,d,K,g,/,e,?]? @@ -1,2 +1,3 @@
+	_10
+	+15
+	_20
+	(1/2) Stage this hunk [y,n,q,a,d,j,J,g,/,e,?]?_
+	EOF
+	test_write_lines s y /1,2 | git add -p >actual &&
+	tail -n 5 <actual >actual.trimmed &&
+	test_cmp expect actual.trimmed
+'
+
 test_expect_success 'split hunk "add -p (edit)"' '
 	# Split, say Edit and do nothing.  Then:
 	#
@@ -442,6 +472,18 @@ test_expect_failure 'split hunk "add -p (no, yes, edit)"' '
 	! grep "^+31" actual
 '
 
+test_expect_success 'split hunk with incomplete line at end' '
+	git reset --hard &&
+	printf "missing LF" >>test &&
+	git add test &&
+	test_write_lines before 10 20 30 40 50 60 70 >test &&
+	git grep --cached missing &&
+	test_write_lines s n y q | git add -p &&
+	test_must_fail git grep --cached missing &&
+	git grep before &&
+	test_must_fail git grep --cached before
+'
+
 test_expect_failure 'edit, adding lines to the first hunk' '
 	test_write_lines 10 11 20 30 40 50 51 60 >test &&
 	git reset &&