1 files changed, 16 insertions, 13 deletions

diff --git a/riscos/filename.c b/riscos/filename.c
index 9355c4ffb..799ff3afd 100644
--- a/riscos/filename.c
+++ b/riscos/filename.c
@@ -86,9 +86,9 @@ bool ro_filename_claim(const char *filename) {
 	struct directory *dir;
 	
 	/* extract the prefix */
-	sprintf(dir_prefix, filename);
+	strcpy(dir_prefix, filename);
 	for (i = 0, last = dir_prefix; i < 3; i++)
-		while (*last++ != '.');
+		while (*last && *last++ != '.');
 	i = atoi(last);
 	last[0] = '\0';
 	
@@ -177,11 +177,9 @@ static struct directory *ro_filename_create_directory(const char *prefix) {
 	int result, index;
 	struct directory *old_dir, *new_dir, *prev_dir = NULL;
 	char dir_prefix[16];
-	
+
 	/* get the lowest unique prefix, or use the provided one */
-	if (prefix) {
-		strcpy(dir_prefix, prefix);
-	} else {
+	if (!prefix) {
 		sprintf(dir_prefix, "00.00.00.");
 		for (index = 1, old_dir = root; old_dir;
 				index++, old_dir = old_dir->next) {
@@ -192,8 +190,9 @@ static struct directory *ro_filename_create_directory(const char *prefix) {
 					((index >> 6) & 63),
 					((index >> 0) & 63));
 		}
+		prefix = dir_prefix;
 	}
-	
+
 	/* allocate a new directory */
 	new_dir = (struct directory *)calloc(1,
 			sizeof(struct directory));
@@ -201,12 +200,13 @@ static struct directory *ro_filename_create_directory(const char *prefix) {
 		LOG(("No memory for calloc()"));
 		return NULL;
 	}
-	strcpy(new_dir->prefix, dir_prefix);
+	strncpy(new_dir->prefix, prefix, 9);
+	new_dir->prefix[9] = '\0';
 
 	/* link into the tree, sorted by prefix. */
 	for (old_dir = root; old_dir; prev_dir = old_dir,
 			old_dir = old_dir->next) {
-		 result = strcmp(old_dir->prefix, dir_prefix);
+		 result = strcmp(old_dir->prefix, prefix);
 		 if (result == 0) {
 			free(new_dir);
 			return old_dir;
@@ -225,12 +225,15 @@ static struct directory *ro_filename_create_directory(const char *prefix) {
 	sprintf(ro_filename_directory, "%s.", CACHE_FILENAME_PREFIX);
 	last_1 = ro_filename_directory + strlen(CACHE_FILENAME_PREFIX) + 1;
 	last_2 = new_dir->prefix;
-	for (int i = 0; i < 3; i++) {
+	for (int i = 0; i < 3 && *last_2; i++) {
 		*last_1++ = *last_2++;
-		while (*last_2 != '.')
+		while (*last_2 && *last_2 != '.')
 			*last_1++ = *last_2++;
-		last_1[0] = '\0';
-		xosfile_create_dir(ro_filename_directory, 0);
+		if (*last_2) {
+			last_1[0] = '\0';
+			xosfile_create_dir(ro_filename_directory, 0);
+		}
 	}
+
 	return new_dir;
 }