fix: memory issues, parser errors and get_ast_if returning always NULL

src/execution/execution_helpers.c

@@ -201,6 +201,8 @@ int exec_ast_command(struct ast_command *command, struct hash_map *vars)
 
 int exec_ast_if(struct ast_if *if_node, struct hash_map *vars)
 {
+    if (if_node == NULL)
+        return 2;
     int cond = execution(if_node->condition, vars);
     if (cond == 0)
         return execution(if_node->then_clause, vars);

src/parser/grammar.c

@@ -140,6 +140,7 @@ bool grammar_init(void)
 
     // Element
     add_first(RULE_ELEMENT, TOKEN_WORD);
+    add_first(RULE_ELEMENT, TOKEN_ASSIGNMENT_WORD);
     add_firsts(RULE_ELEMENT, first(RULE_REDIRECTION));
 
     // Prefix

src/parser/grammar_basic.c

@@ -281,7 +281,7 @@ struct ast *parse_simple_command(struct lexer_context *ctx)
 struct ast *parse_element(struct lexer_context *ctx)
 {
     struct token *token = PEEK_TOKEN();
-    if (token->type == TOKEN_WORD)
+    if (token->type == TOKEN_WORD || token->type == TOKEN_ASSIGNMENT_WORD)
     {
         token = POP_TOKEN();
         return ast_create_word(token->data);

src/utils/ast/ast_if.c

@@ -19,7 +19,7 @@ struct ast *ast_create_if(struct ast *condition, struct ast *then_clause,
 
 struct ast_if *ast_get_if(struct ast *node)
 {
-    if (node == NULL || node->type == AST_IF)
+    if (node == NULL || node->type != AST_IF)
         return NULL;
     return node->data;
 }