From: Christian Weisgerber <naddy@mips.inka.de>
Subject: Re: No-op histedit scripts
To: gameoftrees@openbsd.org
Date: Fri, 14 Jul 2023 20:28:26 +0200

Stefan Sperling:

> Has your work on this been successfully unblocked by the EEXIST error fix?

Yes, it has!

I guess we want to use a stock phrase in the man page to indicate
that the commit/import/tag and histedit operations are only executed
if the log msg/histedit script files have been written from the
invoked editor.  I may not have found the best phrasing yet.

diff refs/heads/main refs/heads/histedit
commit - 1494a06e4ce25cf1beafa90b6b1f98bdebf9e7e2
commit + d9e93be4ebec9dd8fd002bbee5c6269b212bc70a
blob - ea3b833f1bc15d5ea3e276e75da0a16f1e29702c
blob + f10f7d4f259e94b489487e17f41eb5dee33b95df
--- got/got.1
+++ got/got.1
@@ -127,6 +127,7 @@ opens a temporary file in an editor where a log messag
 option,
 .Cm got import
 opens a temporary file in an editor where a log message can be written.
+If the temporary file is not written to, the import operation is aborted.
 .It Fl r Ar repository-path
 Use the repository at the specified path.
 If not specified, assume the repository is located at or above the current
@@ -1347,6 +1348,7 @@ opens a temporary file in an editor where a tag messag
 option,
 .Cm got tag
 opens a temporary file in an editor where a tag message can be written.
+If the temporary file is not written to, the tag operation is aborted.
 .It Fl r Ar repository-path
 Use the repository at the specified path.
 If not specified, assume the repository is located at or above the current
@@ -1708,6 +1710,7 @@ options are used together.
 and
 .Fl N
 options are used together.
+If the temporary file is not written to, the commit operation is aborted.
 .Pp
 Show the status of each affected file, using the following status codes:
 .Bl -column YXZ description
@@ -2522,6 +2525,7 @@ options.
 or
 .Fl m
 options.
+If the script file is not written to, the histedit operation is aborted.
 .Pp
 The format of the histedit script is line-based.
 Each line in the script begins with a command name, followed by
blob - e21a92523011eaf67089838f68f9e98950704b11
blob + 2a5d0bd5f3e513f26cad87624b5c5ebbb8eaef14
--- got/got.c
+++ got/got.c
@@ -11969,6 +11969,8 @@ histedit_run_editor(struct got_histedit_list *histedit
     struct got_repository *repo)
 {
 	const struct got_error *err = NULL;
+	struct stat st, st2;
+	struct timespec timeout;
 	char *editor;
 	FILE *f = NULL;
 
@@ -11976,11 +11978,32 @@ histedit_run_editor(struct got_histedit_list *histedit
 	if (err)
 		return err;
 
+	if (stat(path, &st) == -1) {
+		err = got_error_from_errno2("stat", path);
+		goto done;
+	}
+
 	if (spawn_editor(editor, path) == -1) {
 		err = got_error_from_errno("failed spawning editor");
 		goto done;
 	}
 
+	timeout.tv_sec = 0;
+	timeout.tv_nsec = 1;
+	nanosleep(&timeout,  NULL);
+
+	if (stat(path, &st2) == -1) {
+		err = got_error_from_errno2("stat", path);
+		goto done;
+	}
+
+	if (st.st_size == st2.st_size &&
+	    timespeccmp(&st.st_mtim, &st2.st_mtim, ==)) {
+		err = got_error_msg(GOT_ERR_EMPTY_HISTEDIT,
+                    "no changes made to histedit script, aborting");
+		goto done;
+	}
+
 	f = fopen(path, "re");
 	if (f == NULL) {
 		err = got_error_from_errno("fopen");
-- 
Christian "naddy" Weisgerber                          naddy@mips.inka.de