commit 314a6357a2a91eaa8a8f0f04dcfa5b26a59c4fb2
from: Stefan Sperling <stsp@stsp.name>
date: Mon May 13 18:45:34 2019 UTC

got commit can't use unveil with an editor

Theo says unveil(2) is supposed to traverse exec(2) (though
this seems to be broken or not implemented at present).
In which case the commmit message editor would find itself
without access to files it needs (startup config files,
shared libs, user's home dir, etc.)

Apply unveil after the log message has been written.

commit - 08680430768530f8c5623618e07a4cf068a9cc1f
commit + 314a6357a2a91eaa8a8f0f04dcfa5b26a59c4fb2
blob - 23370a0ae3daea7b02c31c7e2a767bf51d0ba581
blob + 3ef3e75a562a7fdadd4e8d235c892780740d21f3
--- got/got.c
+++ got/got.c
@@ -223,7 +223,7 @@ get_editor(char **abspath)
 
 static const struct got_error *
 apply_unveil(const char *repo_path, int repo_read_only,
-    const char *worktree_path, int create_worktree, char **editor)
+    const char *worktree_path, int create_worktree)
 {
 	const struct got_error *err;
 	static char err_msg[MAXPATHLEN + 36];
@@ -246,19 +246,7 @@ apply_unveil(const char *repo_path, int repo_read_only
 		}
 
 		if (err && (err->code != GOT_ERR_ERRNO || errno != EISDIR))
-			return err;
-	}
-
-	if (editor) {
-		err = get_editor(editor);
-		if (err)
 			return err;
-		if (unveil(*editor, "x") != 0) {
-			err = got_error_from_errno2("unveil", *editor);
-			free(*editor);
-			*editor = NULL;
-			return err;
-		}
 	}
 
 	if (repo_path && unveil(repo_path, repo_read_only ? "r" : "rwc") != 0)
@@ -442,8 +430,7 @@ cmd_checkout(int argc, char *argv[])
 	if (error != NULL)
 		goto done;
 
-	error = apply_unveil(got_repo_get_path(repo), 0, worktree_path, 1,
-	    NULL);
+	error = apply_unveil(got_repo_get_path(repo), 0, worktree_path, 1);
 	if (error)
 		goto done;
 
@@ -581,7 +568,7 @@ cmd_update(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 0,
-	    got_worktree_get_root_path(worktree), 0, NULL);
+	    got_worktree_get_root_path(worktree), 0);
 	if (error)
 		goto done;
 
@@ -953,7 +940,7 @@ cmd_log(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 1,
-	    worktree ? got_worktree_get_root_path(worktree) : NULL, 0, NULL);
+	    worktree ? got_worktree_get_root_path(worktree) : NULL, 0);
 	if (error)
 		goto done;
 
@@ -1215,7 +1202,7 @@ cmd_diff(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 1,
-	    worktree ? got_worktree_get_root_path(worktree) : NULL, 0, NULL);
+	    worktree ? got_worktree_get_root_path(worktree) : NULL, 0);
 	if (error)
 		goto done;
 
@@ -1375,7 +1362,7 @@ cmd_blame(int argc, char *argv[])
 	if (error != NULL)
 		goto done;
 
-	error = apply_unveil(got_repo_get_path(repo), 1, NULL, 0, NULL);
+	error = apply_unveil(got_repo_get_path(repo), 1, NULL, 0);
 	if (error)
 		goto done;
 
@@ -1603,7 +1590,7 @@ cmd_tree(int argc, char *argv[])
 	if (error != NULL)
 		goto done;
 
-	error = apply_unveil(got_repo_get_path(repo), 1, NULL, 0, NULL);
+	error = apply_unveil(got_repo_get_path(repo), 1, NULL, 0);
 	if (error)
 		goto done;
 
@@ -1732,7 +1719,7 @@ cmd_status(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 1,
-	    got_worktree_get_root_path(worktree), 0, NULL);
+	    got_worktree_get_root_path(worktree), 0);
 	if (error)
 		goto done;
 
@@ -1903,7 +1890,7 @@ cmd_ref(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), do_list,
-	    worktree ? got_worktree_get_root_path(worktree) : NULL, 0, NULL);
+	    worktree ? got_worktree_get_root_path(worktree) : NULL, 0);
 	if (error)
 		goto done;
 
@@ -1982,7 +1969,7 @@ cmd_add(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 1,
-	    got_worktree_get_root_path(worktree), 0, NULL);
+	    got_worktree_get_root_path(worktree), 0);
 	if (error)
 		goto done;
 
@@ -2068,7 +2055,7 @@ cmd_rm(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 1,
-	    got_worktree_get_root_path(worktree), 0, NULL);
+	    got_worktree_get_root_path(worktree), 0);
 	if (error)
 		goto done;
 
@@ -2145,7 +2132,7 @@ cmd_revert(int argc, char *argv[])
 		goto done;
 
 	error = apply_unveil(got_repo_get_path(repo), 1,
-	    got_worktree_get_root_path(worktree), 0, NULL);
+	    got_worktree_get_root_path(worktree), 0);
 	if (error)
 		goto done;
 
@@ -2210,6 +2197,7 @@ struct collect_commit_logmsg_arg {
 	const char *cmdline_log;
 	const char *editor;
 	const char *worktree_path;
+	const char *repo_path;
 	char *logmsg_path;
 
 };
@@ -2311,6 +2299,10 @@ collect_commit_logmsg(struct got_pathlist_head *commit
 	}
 done:
 	free(template);
+
+	/* Editor is done; we can now apply unveil(2) */
+	if (err == NULL)
+		err = apply_unveil(a->repo_path, 0, a->worktree_path, 0);
 	return err;
 }
 
@@ -2371,14 +2363,22 @@ cmd_commit(int argc, char *argv[])
 	if (error != NULL)
 		goto done;
 
-	error = apply_unveil(got_repo_get_path(repo), 0,
-	    got_worktree_get_root_path(worktree), 0, &editor);
+	/*
+	 * unveil(2) traverses exec(2); if an editor is used we have
+	 * to apply unveil after the log message has been written.
+	 */
+	if (logmsg == NULL || strlen(logmsg) == 0)
+		error = get_editor(&editor);
+	else
+		error = apply_unveil(got_repo_get_path(repo), 0,
+		    got_worktree_get_root_path(worktree), 0);
 	if (error)
 		goto done;
 
 	cl_arg.editor = editor;
 	cl_arg.cmdline_log = logmsg;
 	cl_arg.worktree_path = got_worktree_get_root_path(worktree);
+	cl_arg.repo_path = got_repo_get_path(repo);
 	cl_arg.logmsg_path = NULL;
 	error = got_worktree_commit(&id, worktree, path, got_author, NULL,
 	    collect_commit_logmsg, &cl_arg, print_status, NULL, repo);