Merge pull request #2 from LebedevRI/exiv2-thubms-upd

Cleanup of several broken bits of the exiv2 thumbnail code

src/common/camera_control.c

@@ -933,8 +933,8 @@ int _camctl_recursive_get_previews(const dt_camctl_t *c, dt_camera_preview_flags
               char fullpath[512];
               snprintf(fullpath, sizeof(fullpath), "%s/%s/%s", c->active_camera->port + 5, path, filename);
               uint8_t *jpg; // gphoto takes care of freeing img eventually
-              uint32_t size;
-              if (dt_exif_get_thumbnail(fullpath, &jpg, &size))
+              size_t size;
+              if(!dt_exif_get_thumbnail(fullpath, &jpg, &size))
                 gp_file_set_data_and_size(preview, (char *) jpg, size);
             }
           }

src/common/exif.cc

@@ -824,7 +824,8 @@ int dt_exif_read_from_blob(dt_image_t *img, uint8_t *blob, const int size)
 /**
  * Get the largest possible thumbnail from the image
  */
-int dt_exif_get_thumbnail(const char *path, uint8_t **buffer, uint32_t *size) {
+int dt_exif_get_thumbnail(const char *path, uint8_t **buffer, size_t *size)
+{
   try
   {
     Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(path);
@@ -847,25 +848,28 @@ int dt_exif_get_thumbnail(const char *path, uint8_t **buffer, uint32_t *size) {
     // Get the selected preview image
     Exiv2::PreviewImage preview = loader.getPreviewImage(selected);
     const unsigned  char *tmp = preview.pData();
-    uint32_t size = preview.size();
+    size_t _size = preview.size();
 
-    // Workaround the fact that exiv2 sometimes returns prepended garbage 
-    while (size > 4 && (tmp[0] != 0xff || tmp[1] != 0xd8)) {
+    // Workaround the fact that exiv2 sometimes returns prepended garbage
+    while(_size > 4 && (tmp[0] != 0xff || tmp[1] != 0xd8))
+    {
       tmp++;
-      size--;
+      _size--;
     }
-    if (size == 0) {
+    if(_size == 0)
+    {
       std::cerr << "[exiv2] thumbnail doesn't seem to be a JPG " << path << std::endl;
       return 1;
     }
 
-    *buffer = (uint8_t *)malloc((size_t) size);
+    *size = _size;
+    *buffer = (uint8_t *)malloc(_size);
     if(!*buffer) {
       std::cerr << "[exiv2] couldn't allocate memory for thumbnail for" << path << std::endl;
       return 1;
     }
-    memcpy(*buffer, tmp, size);
     //std::cerr << "[exiv2] "<< path << ": found thumbnail "<< preview.width() << "x" << preview.height() << std::endl;
+    memcpy(*buffer, tmp, _size);
 
 
     return 0;

src/common/exif.h

@@ -51,7 +51,7 @@ int dt_exif_xmp_attach(const int imgid, const char *filename);
 int dt_exif_xmp_read(dt_image_t *img, const char *filename, const int history_only);
 
 /** fetch largest exif thumbnail jpg bytestream into buffer*/
-int dt_exif_get_thumbnail(const char *path, uint8_t **buffer, uint32_t *size);
+int dt_exif_get_thumbnail(const char *path, uint8_t **buffer, size_t *size);
 
 /** thread safe init and cleanup. */
 void dt_exif_init();

src/common/imageio.c

@@ -61,27 +61,35 @@
 // load a full-res thumbnail:
 int dt_imageio_large_thumbnail(const char *filename, uint8_t **buffer, int32_t *width, int32_t *height)
 {
+  int res = 1;
+
   // Get the JPG embedded in the raw
-  uint8_t *jpgbuffer;
-  uint32_t jpgbuffersize;
+  uint8_t *jpgbuffer = NULL;
+  size_t jpgbuffersize;
 
   if(dt_exif_get_thumbnail(filename, &jpgbuffer, &jpgbuffersize)) return 1;
 
   // Decompress the JPG into our own memory format
   dt_imageio_jpeg_t jpg;
-  if(dt_imageio_jpeg_decompress_header(jpgbuffer, jpgbuffersize, &jpg))
-    return 1;
+  if(dt_imageio_jpeg_decompress_header(jpgbuffer, jpgbuffersize, &jpg)) goto error;
+
   *buffer = (uint8_t *)malloc((size_t)sizeof(uint8_t) * jpg.width * jpg.height * 4);
-  if(!*buffer) return 1;
+  if(!*buffer) goto error;
+
   *width = jpg.width;
   *height = jpg.height;
   if(dt_imageio_jpeg_decompress(&jpg, *buffer))
   {
     free(*buffer);
     *buffer = 0;
-    return 1;
+    goto error;
   }
-  return 0;
+
+  res = 0;
+
+error:
+  free(jpgbuffer);
+  return res;
 }
 
 void dt_imageio_flip_buffers(char *out, const char *in, const size_t bpp, const int wd, const int ht,

src/libs/import.c

@@ -596,7 +596,7 @@ static void _lib_import_update_preview(GtkFileChooser *file_chooser, gpointer da
   if(!have_preview)
   {
     uint8_t *buffer;
-    uint32_t size;
+    size_t size;
     if (!dt_exif_get_thumbnail(filename, &buffer, &size)) {
       // Scale the image to the correct size
       GdkPixbuf *tmp;