From bcbab955dc7c778d2ded60b210c48a449e799a7e Mon Sep 17 00:00:00 2001
From: jjgarcia <jjgarcia>
Date: Tue, 22 Feb 2005 17:43:56 +0000
Subject: [PATCH] Ensure that strings in pathnames are valid C strings

---
 src/CHANGELOG    |  3 +++
 src/c/pathname.d | 31 ++++++++++++++++++++++---------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/src/CHANGELOG b/src/CHANGELOG
index 68977380e..19f5e3e44 100644
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -22,6 +22,9 @@ ECL 0.9f
 
  - ext:c-uint-max and ext:c-ulong-max did not have the right bignum value.
 
+ - All strings in a pathname must be valid C strings, with a null terminating
+   character and no fill pointer.
+
 * Visible changes:
 
  - Multithreaded ECL now in Windows, either with Microsoft VC++
diff --git a/src/c/pathname.d b/src/c/pathname.d
index 629ebb362..85c1a9bb8 100644
--- a/src/c/pathname.d
+++ b/src/c/pathname.d
@@ -37,8 +37,20 @@
 typedef int (*delim_fn)(int);
 
 static cl_object
-check_directory(cl_object directory, bool logical)
+ensure_simple_string(cl_object s)
 {
+	return (type_of(s) == t_string)? coerce_to_simple_string(s) : s;
+}
+
+static cl_object
+destructively_check_directory(cl_object directory, bool logical)
+{
+	/* This function performs two tasks
+	 * 1) It ensures that the list is a valid directory list
+	 * 2) It ensures that all strings in the list are valid C strings without fill pointer
+	 *    All strings are copied, thus avoiding problems with the user modifying the
+	 *    list that was passed to MAKE-PATHNAME.
+	 */
 	/* INV: directory is always a list */
 	cl_object ptr;
 	int i;
@@ -66,6 +78,7 @@ check_directory(cl_object directory, bool logical)
 			if (i > 0)
 				return @':error';
 		} else if (type_of(item) == t_string) {
+			CAR(ptr) = copy_simple_string(item);
 			if (logical)
 				continue;
 			if (strcmp(item->string.self,".")==0) {
@@ -102,7 +115,7 @@ make_pathname(cl_object host, cl_object device, cl_object directory,
 		}
 		goto ERROR;
 	case t_cons: {
-		cl_object aux = check_directory(cl_copy_list(directory), 1);
+		cl_object aux = destructively_check_directory(cl_copy_list(directory), 1);
 		if (aux != @':error') {
 			directory = aux;
 			break;
@@ -137,12 +150,12 @@ make_pathname(cl_object host, cl_object device, cl_object directory,
 				 @':type', type,
 				 @':version', version));
 	}
-	x->pathname.host = host;
-	x->pathname.device = device;
+	x->pathname.host = ensure_simple_string(host);
+	x->pathname.device = ensure_simple_string(device);
 	x->pathname.directory = directory;
-	x->pathname.name = name;
-	x->pathname.type = type;
-	x->pathname.version = version;
+	x->pathname.name = ensure_simple_string(name);
+	x->pathname.type = ensure_simple_string(type);
+	x->pathname.version = ensure_simple_string(version);
 	return(x);
 }
 
@@ -437,7 +450,7 @@ parse_namestring(const char *s, cl_index start, cl_index end, cl_index *ep,
 	if (CONSP(path)) {
 		if (CAR(path) != @':relative' && CAR(path) != @':absolute')
 			path = CONS(@':absolute', path);
-		path = check_directory(path, TRUE);
+		path = destructively_check_directory(path, TRUE);
 	}
 	if (path == @':error')
 		return Cnil;
@@ -509,7 +522,7 @@ parse_namestring(const char *s, cl_index start, cl_index end, cl_index *ep,
 		if (CAR(path) != @':relative' && CAR(path) != @':absolute')
 			path = CONS(@':relative', path);
 		path = tilde_expand(path);
-		path = check_directory(path, FALSE);
+		path = destructively_check_directory(path, FALSE);
 	}
 	if (path == @':error')
 		return Cnil;