config: Improve reading lines from configuration file (#1034)

With this commit some unexpected behavior redarding the configuration
file is addressed. Also, some warnings have been added for cases which
still lead to unreliable reading of the configuration file.

Resolves #1034.

sway/commands.c

@@ -482,6 +482,9 @@ struct cmd_results *config_command(char *exec, enum cmd_status block) {
 	sway_log(L_INFO, "handling config command '%s'", exec);
 	// Endblock
 	if (**argv == '}') {
+		if (1 != argc) {
+			sway_log(L_ERROR, "Note: Currently no other commands on lines with '}' are supported.");
+		}
 		results = cmd_results_new(CMD_BLOCK_END, NULL, NULL);
 		goto cleanup;
 	}

sway/config.c

@@ -1,3 +1,4 @@
+#include <ctype.h>
 #include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
@@ -620,18 +621,91 @@ bool load_include_configs(const char *path, struct sway_config *config) {
 	return true;
 }
 
+static inline char* handle_parentheses(FILE* const file, char* line,
+		unsigned int* const line_number) {
+	if (file && line) {
+		const size_t line_length = strlen(line);
+		if (1 < line_length && line[line_length-2u] != '{') {
+			char* next_line = NULL;
+			while (!feof(file) && !next_line) {
+				next_line = read_line(file);
+				if (line_number) {
+					++(*line_number);
+				}
+				if (next_line && is_empty(next_line)) {
+					free(next_line);
+					next_line = NULL;
+					continue;
+				}
+			}
+			if (next_line) {
+				if (next_line[0] == '{') {
+
+					if (!is_empty(next_line+1)) {
+						if (line_number) {
+							sway_log(L_ERROR, "Warning: Config (%u): Move additional commands to the "
+								"next line after '{'.", *line_number);
+						} else {
+							sway_log(L_ERROR, "Warning: Config: Move additional commands to the next "
+								"line after '{'.");
+						}
+					}
+
+					const size_t new_size = strlen(line) + strlen(next_line);
+					char* concat_line = malloc(new_size);
+					if (concat_line) {
+						line[strlen(line)-1] = '\0';
+						snprintf(concat_line, new_size, "%s %s", line, next_line);
+						free(line);
+						free(next_line);
+						line = concat_line;
+						next_line = NULL;
+					} else {
+						sway_log(L_ERROR, "Error: get_config_line(): Allocation of %zu bytes "
+							"was not successful.", new_size);
+					}
+				}
+			}
+		}
+	}
+	return line;
+}
+
+static inline char* get_config_line(FILE* const file, const enum cmd_status block,
+		unsigned int* const line_number) {
+	char* line = NULL;
+	if (file) {
+		line = read_line(file);
+		if (line_number) {
+			++(*line_number);
+		}
+		if (line) {
+			if (block == CMD_BLOCK_END) {
+				if (0 == strncmp(line, "mode", 4u)  ||
+						0 == strncmp(line, "bar", 3u)) {
+					line = handle_parentheses(file, line, line_number);
+				}
+			}else if (block == CMD_BLOCK_BAR) {
+				if (0 == strncmp(line, "colors", 5u)) {
+					line = handle_parentheses(file, line, line_number);
+				}
+			}
+		}
+	}
+	return line;
+}
+
 bool read_config(FILE *file, struct sway_config *config) {
 	bool success = true;
 	enum cmd_status block = CMD_BLOCK_END;
 
-	int line_number = 0;
+	unsigned int line_number = 0u;
 	char *line;
 	while (!feof(file)) {
-		line = read_line(file);
+		line = get_config_line(file, block, &line_number);
 		if (!line) {
 			continue;
 		}
-		line_number++;
 		struct cmd_results *res;
 		if (block == CMD_BLOCK_COMMANDS) {
 			// Special case