From fb26f3bbb7229fc20c8e79c26d00f4e96a4feb89 Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Mon, 19 Sep 2016 12:06:07 -0400
Subject: [PATCH] fix divide by zero, use non-opaque type for file_archive
 functions

---
 libretro-common/file/archive_file.c         | 40 ++++++++-------------
 libretro-common/include/file/archive_file.h | 15 ++++++--
 2 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/libretro-common/file/archive_file.c b/libretro-common/file/archive_file.c
index 19f1be4a38..48fca17fd5 100644
--- a/libretro-common/file/archive_file.c
+++ b/libretro-common/file/archive_file.c
@@ -47,21 +47,10 @@
 #include <lists/string_list.h>
 #include <string/stdstring.h>
 
-typedef struct
-{
-#ifdef HAVE_MMAP
-   int fd;
-#endif
-   void *data;
-   size_t size;
-} file_archive_file_data_t;
-
 #ifdef HAVE_MMAP
 /* Closes, unmaps and frees. */
-void file_archive_free(void *handle)
+void file_archive_free(file_archive_file_data_t *data)
 {
-   file_archive_file_data_t *data = (file_archive_file_data_t*)handle;
-
    if (!data)
       return;
 
@@ -72,23 +61,21 @@ void file_archive_free(void *handle)
    free(data);
 }
 
-const uint8_t *file_archive_data(void *handle)
+const uint8_t *file_archive_data(file_archive_file_data_t *data)
 {
-   file_archive_file_data_t *data = (file_archive_file_data_t*)handle;
    if (!data)
       return NULL;
    return (const uint8_t*)data->data;
 }
 
-static size_t file_archive_size(void *handle)
+static size_t file_archive_size(file_archive_file_data_t *data)
 {
-   file_archive_file_data_t *data = (file_archive_file_data_t*)handle;
    if (!data)
       return 0;
    return data->size;
 }
 
-static void *file_archive_open(const char *path)
+static file_archive_file_data_t* file_archive_open(const char *path)
 {
    file_archive_file_data_t *data = (file_archive_file_data_t*)calloc(1, sizeof(*data));
 
@@ -123,9 +110,8 @@ error:
 #else
 
 /* Closes, unmaps and frees. */
-void file_archive_free(void *handle)
+void file_archive_free(file_archive_file_data_t *data)
 {
-   file_archive_file_data_t *data = (file_archive_file_data_t*)handle;
    if (!data)
       return;
    if(data->data)
@@ -133,23 +119,21 @@ void file_archive_free(void *handle)
    free(data);
 }
 
-const uint8_t *file_archive_data(void *handle)
+const uint8_t *file_archive_data(file_archive_file_data_t *data)
 {
-   file_archive_file_data_t *data = (file_archive_file_data_t*)handle;
    if (!data)
       return NULL;
    return (const uint8_t*)data->data;
 }
 
-static size_t file_archive_size(void *handle)
+static size_t file_archive_size(file_archive_file_data_t *data)
 {
-   file_archive_file_data_t *data = (file_archive_file_data_t*)handle;
    if (!data)
       return 0;
    return data->size;
 }
 
-static void *file_archive_open(const char *path)
+static file_archive_file_data_t* file_archive_open(const char *path)
 {
    ssize_t ret            = -1;
    bool read_from_file    = false;
@@ -475,7 +459,13 @@ static bool file_archive_parse_file(const char *file, const char *valid_exts,
 int file_archive_parse_file_progress(file_archive_transfer_t *state)
 {
    /* FIXME: this estimate is worse than before */
-   ptrdiff_t delta = state->directory - state->data;
+   ptrdiff_t delta = 0;
+
+   if (!state || state->archive_size == 0)
+      return 0;
+
+   delta = state->directory - state->data;
+
    return delta * 100 / state->archive_size;
 }
 
diff --git a/libretro-common/include/file/archive_file.h b/libretro-common/include/file/archive_file.h
index cfc4f077b6..ec464204f0 100644
--- a/libretro-common/include/file/archive_file.h
+++ b/libretro-common/include/file/archive_file.h
@@ -46,9 +46,18 @@ typedef struct file_archive_handle
    const struct file_archive_file_backend *backend;
 } file_archive_file_handle_t;
 
+typedef struct
+{
+#ifdef HAVE_MMAP
+   int fd;
+#endif
+   void *data;
+   size_t size;
+} file_archive_file_data_t;
+
 typedef struct file_archive_transfer
 {
-   void *handle;
+   file_archive_file_data_t *handle;
    void *stream;
    const uint8_t *footer;
    const uint8_t *directory;
@@ -194,12 +203,12 @@ struct string_list* file_archive_file_list_new(const char *path,
 
 struct string_list* file_archive_filename_split(const char *path);
 
-const uint8_t* file_archive_data(void *handle);
+const uint8_t* file_archive_data(file_archive_file_data_t *data);
 
 int file_archive_parse_file_init(file_archive_transfer_t *state,
       const char *file);
 
-void file_archive_free(void *handle);
+void file_archive_free(file_archive_file_data_t *data);
 
 const struct file_archive_file_backend* file_archive_get_zlib_file_backend(void);
 const struct file_archive_file_backend* file_archive_get_7z_file_backend(void);