fixup environ handling

libc/main.c

@@ -1,5 +1,6 @@
 #include <stdint.h>
 #include <stddef.h>
+#include <stdlib.h>
 
 #include <syscall.h>
 #include <syscall_nums.h>
@@ -77,6 +78,44 @@ static void _libc_init(void) {
 			break;
 		}
 	}
+	if (!environ) {
+		environ = malloc(sizeof(char *) * 4);
+		environ[0] = NULL;
+		environ[1] = NULL;
+		environ[2] = NULL;
+		environ[3] = NULL;
+		_environ_size = 4;
+	} else {
+		/* Find actual size */
+		int size = 0;
+
+		char ** tmp = environ;
+		while (*tmp) {
+			size++;
+			tmp++;
+		}
+
+		if (size < 4) {
+			_environ_size = 4;
+		} else {
+			/* Multiply by two */
+			_environ_size = size * 2;
+		}
+
+		char ** new_environ = malloc(sizeof(char*) * _environ_size);
+		int i = 0;
+		while (i < _environ_size && environ[i]) {
+			new_environ[i] = environ[i];
+			i++;
+		}
+
+		while (i < _environ_size) {
+			new_environ[i] = NULL;
+			i++;
+		}
+
+		environ = new_environ;
+	}
 	_argv_0 = __get_argv()[0];
 }
 

libc/stdlib/putenv.c

@@ -15,34 +15,6 @@ static int why_no_strnstr(char * a, char * b, int n) {
 }
 
 int putenv(char * string) {
-	if (_environ_size == 0) {
-		/* Find actual size */
-		int size = 0;
-
-		char ** tmp = environ;
-		while (*tmp) {
-			size++;
-			tmp++;
-		}
-
-		/* Multiply by two */
-		_environ_size = size * 2;
-
-		char ** new_environ = malloc(sizeof(char*) * _environ_size);
-		int i = 0;
-		while (environ[i]) {
-			new_environ[i] = environ[i];
-			i++;
-		}
-
-		while (i < _environ_size) {
-			new_environ[i] = NULL;
-			i++;
-		}
-
-		environ = new_environ;
-	}
-
 	char name[strlen(string)];
 	strcpy(name, string);
 	char * c = strchr(name, '=');
@@ -54,19 +26,27 @@ int putenv(char * string) {
 	int s = strlen(name);
 
 	int i;
-	for (i = 0; environ[i]; ++i) {
+	for (i = 0; i < (_environ_size - 1) && environ[i]; ++i) {
 		if (!why_no_strnstr(name, environ[i], s)) {
 			environ[i] = string;
 			return 0;
 		}
 	}
 	/* Not found */
-	if (i >= _environ_size) {
-		environ = realloc(environ, _environ_size * 2);
-		for (int i = _environ_size; i < _environ_size * 2; ++i) {
-			environ[i] = NULL;
+	if (i == _environ_size - 1) {
+		int _new_environ_size = _environ_size * 2;
+		char ** new_environ = malloc(sizeof(char*) * _new_environ_size);
+		int j = 0;
+		while (j < _new_environ_size && environ[j]) {
+			new_environ[j] = environ[j];
+			j++;
 		}
-		_environ_size *= 2;
+		while (j < _new_environ_size) {
+			new_environ[j] = NULL;
+			j++;
+		}
+		_environ_size = _new_environ_size;
+		environ = new_environ;
 	}
 
 	environ[i] = string;