fix: Use NULL as termination condition for variable list

Author: hyperupcall

src/util.c

@@ -161,9 +161,9 @@ struct ExpandStringResult expand_string(char *input, struct ExpandStringVars var
 			memset(var, 0, right - left);
 			strncat(var, left + 1, right - left - 1);
 			bool found = false;
-			for (unsigned int i = 0; i < vars.len; ++i) {
-				if (STR_EQ(var, vars.vars[i].key)) {
-					strcat(output, vars.vars[i].value);
+			for (unsigned int i = 0; vars.pairs[i].key != NULL; ++i) {
+				if (STR_EQ(var, vars.pairs[i].key)) {
+					strcat(output, vars.pairs[i].value);
 					result.code = ES_SUCCESS;
 					found = true;
 				}
@@ -210,11 +210,11 @@ char pwddir[PATH_MAX];
 		strcat(cfgdir, "/.config");
 
 		struct ExpandStringVars vars = {
-			.len = 3,
-			.vars = {
+			.pairs = {
 				{.key = "home", .value = homedir},
 				{.key = "pwd", .value = pwddir},
 				{.key = "cfg", .value = cfgdir},
+				NULL,
 			},
 		};
 

src/util.h

@@ -43,8 +43,7 @@ struct ExpandStringVar {
 };
 
 struct ExpandStringVars {
-	unsigned int len;
-	struct ExpandStringVar vars[100];
+	struct ExpandStringVar pairs[100];
 };
 
 struct ExpandStringResult {

test/test.c

@@ -6,8 +6,7 @@
 
 int main() {
 	struct ExpandStringVars empty_vars = {
-		.len = 0,
-		.vars = {{0}},
+		.pairs = {NULL},
 	};
 
 	// No expansions
@@ -96,9 +95,9 @@ int main() {
 	// Working
 	{
 		struct ExpandStringVars vars = {
-			.len = 1,
-			.vars = {
+			.pairs = {
 				{.key = "word", .value = "cool"},
+				NULL,
 			},
 		};
 		struct ExpandStringResult r = expand_string("${word}/X11", vars);
@@ -108,9 +107,9 @@ int main() {
 
 	{
 		struct ExpandStringVars vars = {
-			.len = 1,
-			.vars = {
+			.pairs = {
 				{.key = "word", .value = "cool"},
+				NULL,
 			},
 		};
 		struct ExpandStringResult r = expand_string("fox-${word}", vars);
@@ -119,10 +118,10 @@ int main() {
 	}
 	{
 		struct ExpandStringVars vars = {
-			.len = 2,
-			.vars = {
+			.pairs = {
 				{.key = "a", .value = "super"},
 				{.key = "b", .value = "epic"},
+				NULL,
 			},
 		};
 		struct ExpandStringResult r = expand_string("fox-${a}_${b}", vars);