ledit

commit fcb4dcfe38932c8c4550b3f6b007d467ee5b7042
parent bab18b62da4d443665698fa3e8bc0e28fc9bbfe0
Author: lumidify <nobody@lumidify.org>
Date:   Sat,  4 Nov 2023 21:18:29 +0100

Don't attempt to open non-regular files

Diffstat:
M
ledit.c
 | 
50
+++++++++++++++++++++++++++++++++++++++++---------

1 file changed, 41 insertions(+), 9 deletions(-)
diff --git a/ledit.c b/ledit.c
@@ -600,42 +600,59 @@ setup(int argc, char *argv[]) {
 	clock_gettime(CLOCK_MONOTONIC, &last);
 	#endif
 
+	/* FIXME: Technically, there's a race condition between checking stat and actually
+	   opening the files. This is mainly important when checking if the file is not a regular
+	   file because that is not an error for functions like fopen, so bad things will happen
+	   if a non-regular file (e.g. a directory) is given to one of the file reading
+	   functions. However, I don't know of any portable way to have one of the open functions
+	   check that, so this is the best I can do. */
 	char *stat_errstr = NULL, *load_errstr = NULL, *load_default_errstr = NULL;
 	char *cfgfile = NULL;
 	if (!opt_filename) {
 		uid_t uid = getuid();
 		struct passwd *pw = getpwuid(uid);
 		if (!pw) {
-			fprintf(stderr, "Unable to determine home directory\n");
+			stat_errstr = ledit_strdup("Unable to determine home directory to load default configuration file.");
 		} else {
 			cfgfile = ledit_strcat(pw->pw_dir, "/.leditrc");
 			struct stat cfgst;
-			/* FIXME: maybe only when ENOENT? */
 			if (stat(cfgfile, &cfgst)) {
 				free(cfgfile);
 				cfgfile = NULL;
+				if (errno != ENOENT) {
+					stat_errstr = print_fmt("Unable to load configuration file '~/.leditrc': %s", strerror(errno));
+				}
+			} else if (!S_ISREG(cfgst.st_mode)) {
+				stat_errstr = ledit_strdup("Unable to load configuration file '~/.leditrc': Is not a regular file.");
+				free(cfgfile);
+				cfgfile = NULL;
 			}
 		}
 	} else {
 		struct stat cfgst;
 		if (stat(opt_filename, &cfgst)) {
-			stat_errstr = print_fmt("Unable to load configuration file '%s'", opt_filename);
-			fprintf(stderr, "%s\n", stat_errstr);
+			stat_errstr = print_fmt("Unable to load configuration file '%s': %s", opt_filename, strerror(errno));
+		} else if (!S_ISREG(cfgst.st_mode)) {
+			stat_errstr = print_fmt("Unable to load configuration file '%s': Is not a regular file.", opt_filename);
 		} else {
 			cfgfile = ledit_strdup(opt_filename);
 		}
 	}
+	if (stat_errstr)
+		fprintf(stderr, "%s\n", stat_errstr);
 	if (config_loadfile(&common, cfgfile, &load_errstr)) {
 		fprintf(stderr, "%s\n", load_errstr);
+		fprintf(stderr, "Unable to load configuration '%s'\n", cfgfile ? cfgfile : "default config");
 		int failure = 1;
 		if (cfgfile) {
 			/* retry with default config */
 			failure = config_loadfile(&common, NULL, &load_default_errstr);
 		}
 		if (failure) {
-			fprintf(stderr, "Unable to load configuration: %s\n", load_errstr);
-			if (load_default_errstr)
-				fprintf(stderr, "Also unable to load default configuration: %s\n", load_default_errstr);
+			if (load_default_errstr) {
+				fprintf(stderr, "%s\n", load_default_errstr);
+				fprintf(stderr, "Also unable to load default configuration\n");
+			}
 			free(stat_errstr);
 			free(load_errstr);
 			free(load_default_errstr);
@@ -683,6 +700,8 @@ setup(int argc, char *argv[]) {
 		int readonly = 0;
 		int error = 0;
 		/* FIXME: maybe copy vi and open file in /tmp by default? */
+		/* FIXME: when other methods of opening files (:r, etc.) are supported,
+		   all this checking needs to be moved to a place where it can be reused */
 		if (stat(argv[0], &sb)) {
 			if (errno == ENOENT) {
 				/* note that there may still be a failure
@@ -690,18 +709,32 @@ setup(int argc, char *argv[]) {
 				   the path does not exist */
 				newfile = 1;
 			} else {
+				fprintf(
+				    stderr, "Error opening file '%s': %s\n",
+				    argv[0], strerror(errno)
+				);
 				window_show_message_fmt(
 				    view->window, "Error opening file '%s': %s",
 				    argv[0], strerror(errno)
 				);
 				error = 1;
 			}
+		} else if (!S_ISREG(sb.st_mode)) {
+			fprintf(stderr, "Error opening file '%s': Is not a regular file\n", argv[0]);
+			window_show_message_fmt(
+			    view->window, "Error opening file '%s': Is not a regular file", argv[0]
+			);
+			error = 1;
 		}
 		if (access(argv[0], W_OK)) {
 			readonly = 1;
 		}
-		if (!newfile) {
+		if (!newfile && !error) {
 			if (buffer_load_file(buffer, argv[0], 0, &load_err)) {
+				fprintf(
+				    stderr, "Error opening file '%s': %s\n",
+				    argv[0], load_err
+				);
 				window_show_message_fmt(
 				    view->window, "Error opening file '%s': %s",
 				    argv[0], load_err
@@ -712,7 +745,6 @@ setup(int argc, char *argv[]) {
 		}
 		if (!error) {
 			buffer->filename = ledit_strdup(argv[0]);
-			/* FIXME: show this *in addition* to error */
 			if (!show_error) {
 				if (newfile) {
 					window_show_message_fmt(view->window, "%s: new file", argv[0]);