Handle system errors when launching editor

src/fmail.c

@@ -434,13 +434,19 @@ read_input_from_editor(void)
     FILE *f;
 
     editor = get_editor();
-    command = xmalloc(strlen(editor) + sizeof(tmp_filename) + 1);
 
-    tmp_fd = mkstemp(tmp_filename);
+    if ( (tmp_fd = mkstemp(tmp_filename)) == -1 )
+        err(EXIT_FAILURE, "cannot create temporary file");
+
+    command = xmalloc(strlen(editor) + sizeof(tmp_filename) + 1);
     sprintf(command, "%s %s", editor, tmp_filename);
-    system(command);
 
-    f = fdopen(tmp_fd, "r");
+    if ( system(command) == -1 )
+        err(EXIT_FAILURE, "cannot execute editor '%s'", editor);
+
+    if ( (f = fdopen(tmp_fd, "r")) == NULL )
+        err(EXIT_FAILURE, "cannot open temporary file");
+
     unlink(tmp_filename);
     free(command);