add file operations table and make all frontends use it.

This rationalises the path construction and basename file
operations. The default implementation is POSIX which works for all
frontends except windows, riscos and amiga which have differeing path
separators and rules.

These implementations are significantly more robust than the previous
nine implementations and also do not use unsafe strncpy or buffers
with arbitrary length limits.

These implementations also carry full documentation comments.

1 files changed, 57 insertions, 25 deletions

diff --git a/windows/gui.c b/windows/gui.c
index 0af54ee62..0be75e1e8 100644
--- a/windows/gui.c
+++ b/windows/gui.c
@@ -43,6 +43,7 @@
 #include "utils/log.h"
 #include "utils/messages.h"
 #include "utils/utils.h"
+#include "utils/file.h"
 
 #include "windows/window.h"
 #include "windows/about.h"
@@ -1808,42 +1809,75 @@ nsws_create_main_class(HINSTANCE hinstance) {
 }
 
 /**
- * Return the filename part of a full path
+ * Generate a windows path from one or more component elemnts.
  *
- * \param path full path and filename
- * \return filename (will be freed with free())
+ * If a string is allocated it must be freed by the caller.
+ *
+ * @param[in,out] str pointer to string pointer if this is NULL enough
+ *                    storage will be allocated for the complete path.
+ * @param[in,out] size The size of the space available if \a str not
+ *                     NULL on input and if not NULL set to the total
+ *                     output length on output.
+ * @param[in] nemb The number of elements.
+ * @param[in] ... The elements of the path as string pointers.
+ * @return NSERROR_OK and the complete path is written to str
+ *         or error code on faliure.
  */
-static char *filename_from_path(char *path)
+static nserror windows_mkpath(char **str, size_t *size, size_t nelm, va_list ap)
 {
-	char *leafname;
-
-	leafname = strrchr(path, '\\');
-	if (!leafname)
-		leafname = path;
-	else
-		leafname += 1;
-
-	return strdup(leafname);
+	return vsnstrjoin(str, size, '\\', nelm, ap);
 }
 
 /**
- * Add a path component/filename to an existing path
+ * Get the basename of a file using windows path handling.
+ *
+ * This gets the last element of a path and returns it.
  *
- * \param path buffer containing path + free space
- * \param length length of buffer "path"
- * \param newpart string containing path component to add to path
- * \return true on success
+ * @param[in] path The path to extract the name from.
+ * @param[in,out] str Pointer to string pointer if this is NULL enough
+ *                    storage will be allocated for the path element.
+ * @param[in,out] size The size of the space available if \a
+ *                     str not NULL on input and set to the total
+ *                     output length on output.
+ * @return NSERROR_OK and the complete path is written to str
+ *         or error code on faliure.
  */
-static bool path_add_part(char *path, int length, const char *newpart)
+static nserror windows_basename(const char *path, char **str, size_t *size)
 {
-	if(path[strlen(path) - 1] != '\\')
-		strncat(path, "\\", length);
+	const char *leafname;
+	char *fname;
 
-	strncat(path, newpart, length);
+	if (path == NULL) {
+		return NSERROR_BAD_PARAMETER;
+	}
 
-	return true;
+	leafname = strrchr(path, '\\');
+	if (!leafname) {
+		leafname = path;
+	} else {
+		leafname += 1;
+	}
+
+	fname = strdup(leafname);
+	if (fname == NULL) {
+		return NSERROR_NOMEM;
+	}
+
+	*str = fname;
+	if (size != NULL) {
+		*size = strlen(fname);
+	}
+	return NSERROR_OK;
 }
 
+/* default to using the posix file handling */
+static struct gui_file_table file_table = {
+	.mkpath = windows_mkpath,
+	.basename = windows_basename,
+};
+
+struct gui_file_table *win32_file_table = &file_table;
+
 static struct gui_window_table window_table = {
 	.create = gui_window_create,
 	.destroy = gui_window_destroy,
@@ -1876,8 +1910,6 @@ struct gui_clipboard_table *win32_clipboard_table = &clipboard_table;
 
 
 static struct gui_fetch_table fetch_table = {
-	.filename_from_path = filename_from_path,
-	.path_add_part = path_add_part,
 	.filetype = fetch_filetype,
 	.path_to_url = path_to_url,
 	.url_to_path = url_to_path,