sequencer (rebase -i): implement the 'exec' command

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

sequencer.c

@@ -16,6 +16,7 @@
 #include "refs.h"
 #include "argv-array.h"
 #include "log-tree.h"
+#include "wt-status.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -504,13 +505,15 @@ enum todo_command {
 	TODO_PICK,
 	TODO_REVERT,
 	TODO_EDIT,
+	TODO_EXEC,
 	TODO_NOOP
 };
 
 static const char *todo_command_strings[] = {
 	"pick",
 	"revert",
 	"edit",
+	"exec",
 	"noop"
 };
 
@@ -798,6 +801,12 @@ static int parse_insn_line(struct todo_item *item,
 		return -1;
 	bol += padding;
 
+	if (item->command == TODO_EXEC) {
+		item->arg = bol;
+		item->arg_len = (int)(eol - bol);
+		return 0;
+	}
+
 	end_of_object_name = (char *) bol + strcspn(bol, " \t\n");
 	saved = *end_of_object_name;
 	*end_of_object_name = '\0';
@@ -1139,6 +1148,43 @@ static int error_with_patch(struct commit *commit,
 	return exit_code;
 }
 
+static int do_exec(const char *command_line)
+{
+	const char *child_argv[] = { NULL, NULL };
+	int dirty, status;
+
+	child_argv[0] = command_line;
+	status = run_command_v_opt(child_argv, RUN_USING_SHELL);
+
+	discard_cache(); /* force re-reading of the cache */
+	dirty = require_clean_work_tree("rebase", NULL, 1);
+
+	if (status) {
+		warning("Execution failed: %s\n%s"
+			"You can fix the problem, and then run\n"
+			"\n"
+			"  git rebase --continue\n"
+			"\n",
+			command_line,
+			dirty ? "and made changes to the index and/or the "
+				"working tree\n" : "");
+		if (status == 127)
+			/* command not found */
+			status = 1;
+	}
+	else if (dirty) {
+		warning("Execution succeeded: %s\nbut "
+			"left changes to the index and/or the working tree\n"
+			"Commit or stash your changes, and then run\n"
+			"\n"
+			"  git rebase --continue\n"
+			"\n", command_line);
+		status = 1;
+	}
+
+	return status;
+}
+
 static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 {
 	int res = 0;
@@ -1166,6 +1212,14 @@ static int pick_commits(struct todo_list *todo_list, struct replay_opts *opts)
 				return error_with_patch(commit, opts, res);
 			}
 		}
+		else if (item->command == TODO_EXEC) {
+			char *end_of_arg = (char *)(item->arg + item->arg_len);
+			int saved = *end_of_arg;
+
+			*end_of_arg = '\0';
+			res = do_exec(item->arg);
+			*end_of_arg = saved;
+		}
 		else if (item->command != TODO_NOOP)
 			return error("Unknown command %d", item->command);