fix(susbt/variable): empty variables on their own are removed

src/executing/simple_cmd/simple_cmd_execute.c

@@ -6,7 +6,7 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/03/27 16:21:56 by khais             #+#    #+#             */
-/*   Updated: 2025/04/17 11:16:18 by khais            ###   ########.fr       */
+/*   Updated: 2025/04/17 17:51:25 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -43,13 +43,13 @@ static t_simple_cmd	*post_process_command(t_simple_cmd *cmd, t_minishell *app)
 {
 	simple_cmd_post_process_debug(cmd, app);
 	if (simple_cmd_expand_vars(cmd, app) == NULL)
-		return (simple_cmd_destroy(cmd), NULL);
+		return (NULL);
 	if (simple_cmd_fieldsplit(cmd) == NULL)
-		return (simple_cmd_destroy(cmd), NULL);
+		return (NULL);
 	if (simple_cmd_expand_wildcards(cmd) == NULL)
-		return (simple_cmd_destroy(cmd), NULL);
+		return (NULL);
 	if (simple_cmd_remove_quotes(cmd) == NULL)
-		return (simple_cmd_destroy(cmd), NULL);
+		return (NULL);
 	return (cmd);
 }
 

src/postprocess/expansion/expand_vars.c

@@ -6,7 +6,7 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/04/01 13:34:51 by khais             #+#    #+#             */
-/*   Updated: 2025/04/01 13:36:25 by khais            ###   ########.fr       */
+/*   Updated: 2025/04/17 17:44:53 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
@@ -17,7 +17,8 @@ t_simple_cmd	*simple_cmd_expand_vars(t_simple_cmd *cmd, t_minishell *app)
 {
 	if (cmd == NULL)
 		return (NULL);
-	if (wordlist_var_expansion(cmd->words, app) == NULL)
+	cmd->words = wordlist_var_expansion(cmd->words, app);
+	if (cmd->words == NULL)
 		return (NULL);
 	return (cmd);
 }

src/subst/variable_subst.c

@@ -6,10 +6,11 @@
 /*   By: khais <marvin@42.fr>                       +#+  +:+       +#+        */
 /*                                                +#+#+#+#+#+   +#+           */
 /*   Created: 2025/03/19 17:28:29 by khais             #+#    #+#             */
-/*   Updated: 2025/04/16 18:03:52 by khais            ###   ########.fr       */
+/*   Updated: 2025/04/18 09:22:10 by khais            ###   ########.fr       */
 /*                                                                            */
 /* ************************************************************************** */
 
+#include "../ft_errno.h"
 #include "subst.h"
 #include "../minishell.h"
 #include "replace_substr.h"
@@ -115,8 +116,11 @@ static char	*calculate_replacement(t_worddesc *word, t_minishell *app, size_t i,
 ** Similarly if the character following the '$' is neither '_' or
 ** alphanumerical the dollar is removed except for the appearance of a '\0'
 ** signaling the end of the word.
-** Returns NULL in case of error, or the worddesc pointer word itself if
-** everything went normally.
+** Returns NULL and sets errno in case of error, or the worddesc pointer word
+** itself if everything went normally.
+**
+** returns NULL and does not touch errno if this word should be deleted (because
+** of the expansion of an unquoted empty variable).
 */
 t_worddesc	*word_var_expansion(t_worddesc *word, t_minishell *app)
 {
@@ -133,10 +137,12 @@ t_worddesc	*word_var_expansion(t_worddesc *word, t_minishell *app)
 		{
 			rep = calculate_replacement(word, app, i, &id_len);
 			if (!rep)
-				return (NULL);
+				return (ft_errno(FT_EERRNO), NULL);
 			rep_len = ft_strlen(rep);
 			if (word_update(word, i, id_len, rep) == NULL)
-				return (NULL);
+				return (ft_errno(FT_EERRNO), NULL);
+			if (ft_strlen(word->word) == 0)
+				return (worddesc_destroy(word), NULL);
 		}
 		i += rep_len;
 	}
@@ -149,18 +155,33 @@ t_worddesc	*word_var_expansion(t_worddesc *word, t_minishell *app)
 ** where the introductory '$' character was not single quoted.
 ** We DO NOT take the '\' character into account as an escape character here
 ** under any circumstance per subject requirement.
+**
+** In case of error, all of list is freed.
 */
 t_wordlist	*wordlist_var_expansion(t_wordlist *list, t_minishell *app)
 {
-	t_wordlist	*tmp_list;
+	t_wordlist	*in_list;
+	t_wordlist	*out_list;
+	t_worddesc	*word;
 
-	tmp_list = list;
-	while (tmp_list)
+	in_list = list;
+	out_list = NULL;
+	while (in_list)
 	{
-		if ((tmp_list->word->flags & W_HASDOLLAR)
-			&& word_var_expansion(tmp_list->word, app) == NULL)
-			return (NULL);
-		tmp_list = tmp_list->next;
+		word = wordlist_pop(&in_list);
+		if (word->flags & W_HASDOLLAR)
+		{
+			ft_errno(FT_ESUCCESS);
+			word = word_var_expansion(word, app);
+			if (word == NULL && ft_errno_get() != FT_ESUCCESS)
+			{
+				wordlist_destroy(in_list);
+				wordlist_destroy(out_list);
+				return (NULL);
+			}
+		}
+		if (word != NULL)
+			out_list = wordlist_push(out_list, word);
 	}
-	return (list);
+	return (out_list);
 }

test.sh

@@ -704,4 +704,14 @@ expecting <<"EOF"
 minishell: syntax error near unexpected token `|'
 EOF
 
+when_run <<EOF "empty variables are removed"
+""
+\$EMPTY_NO_VALUE
+echo not \$EMPTY_NO_VALUE printed
+EOF
+expecting <<EOF
+minishell: : command not found
+not printed
+EOF
+
 finalize