Enforce that --confdir must be a directory (#2051)

* Enforce that when we are using --confdir - the path that is passed in has to be a directory and not a file

src/config.d

@@ -221,6 +221,20 @@ final class Config
 			mkdirRecurse(configDirName);
 			// Configure the applicable permissions for the folder
 			configDirName.setAttributes(returnRequiredDirectoryPermisions());
+		} else {
+			// The config path exists
+			// The path that exists must be a directory, not a file
+			if (!isDir(configDirName)) {
+				if (!confdirOption.empty) {
+					// the configuration path was passed in by the user .. user error
+					writeln("ERROR: --confdir entered value is an existing file instead of an existing directory");
+				} else {
+					// other error
+					writeln("ERROR: ~/.config/onedrive is a file rather than a directory");
+				}
+				// Must exit
+				exit(EXIT_FAILURE);	
+			}
 		}
 
 		// configDirName has a trailing /

src/main.d

@@ -146,6 +146,9 @@ int main(string[] args)
 		return EXIT_FAILURE;
 	}
 
+	// confdirOption must be a directory, not a file
+	// - By default ~/.config/onedrive will be used
+	// - If the user is using --confdir , the confdirOption needs to be evaluated when trying to load any file
 	// load configuration file if available
 	auto cfg = new config.Config(confdirOption);
 	if (!cfg.initialize()) {