Add a few more NULL pointer checks.

[platform/upstream/libexif.git] / libexif / exif-loader.c

diff --git a/libexif/exif-loader.c b/libexif/exif-loader.c
index 727d36b..1171485 100644 (file)
--- a/libexif/exif-loader.c
+++ b/libexif/exif-loader.c
@@ -1,6 +1,6 @@
 /* exif-loader.c
  *
- * Copyright © 2002 Lutz Müller <lutz@users.sourceforge.net>
+ * Copyright (c) 2002 Lutz Mueller <lutz@users.sourceforge.net>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -14,21 +14,27 @@
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA  02110-1301  USA.
  */
 
 #include <config.h>
 
 #include <libexif/exif-loader.h>
+#include <libexif/exif-utils.h>
 #include <libexif/i18n.h>
 
+#include <sys/types.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
+#undef JPEG_MARKER_DHT
+#define JPEG_MARKER_DHT  0xc4
 #undef JPEG_MARKER_SOI
 #define JPEG_MARKER_SOI  0xd8
+#undef JPEG_MARKER_DQT
+#define JPEG_MARKER_DQT  0xdb
 #undef JPEG_MARKER_APP0
 #define JPEG_MARKER_APP0 0xe0
 #undef JPEG_MARKER_APP1
@@ -57,12 +63,15 @@ typedef enum {
        EL_DATA_FORMAT_FUJI_RAW
 } ExifLoaderDataFormat;
 
+/*! \internal */
 struct _ExifLoader {
        ExifLoaderState state;
        ExifLoaderDataFormat data_format;
 
-       /* Small buffer used for detection of format */
+       /*! Small buffer used for detection of format */
        unsigned char b[12];
+
+       /*! Number of bytes in the small buffer \c b */
        unsigned char b_len;
 
        unsigned int size;
@@ -75,6 +84,7 @@ struct _ExifLoader {
        ExifMem *mem;
 };
 
+/*! Magic number for EXIF header */
 static const unsigned char ExifHeader[] = {0x45, 0x78, 0x69, 0x66, 0x00, 0x00};
 
 static void *
@@ -93,9 +103,6 @@ exif_loader_alloc (ExifLoader *l, unsigned int i)
        return NULL;
 }
 
-#undef  MIN
-#define MIN(a, b)  (((a) < (b)) ? (a) : (b))
-
 void
 exif_loader_write_file (ExifLoader *l, const char *path)
 {
@@ -103,7 +110,7 @@ exif_loader_write_file (ExifLoader *l, const char *path)
        int size;
        unsigned char data[1024];
 
-       if (!l) 
+       if (!l || !path)
                return;
 
        f = fopen (path, "rb");
@@ -171,10 +178,14 @@ exif_loader_write (ExifLoader *eld, unsigned char *buf, unsigned int len)
                        break;
                }
                break;
+
+       case EL_READ:
        default:
                break;
        }
 
+       if (!len)
+               return 1;
        exif_log (eld->log, EXIF_LOG_CODE_DEBUG, "ExifLoader",
                  "Scanning %i byte(s) of data...", len);
 
@@ -262,7 +273,7 @@ exif_loader_write (ExifLoader *eld, unsigned char *buf, unsigned int len)
                default:
                        switch (eld->b[i]) {
                        case JPEG_MARKER_APP1:
-                               if (!memcmp (eld->b + i + 3, ExifHeader, min(sizeof (ExifHeader), max(0, sizeof (eld->b) - i - 3)))) {
+                         if (!memcmp (eld->b + i + 3, ExifHeader, MIN((ssize_t)(sizeof(ExifHeader)), MAX(0, ((ssize_t)(sizeof(eld->b))) - ((ssize_t)i) - 3)))) {
                                        eld->data_format = EL_DATA_FORMAT_EXIF;
                                } else {
                                        eld->data_format = EL_DATA_FORMAT_JPEG; /* Probably JFIF - keep searching for APP1 EXIF*/
@@ -270,6 +281,8 @@ exif_loader_write (ExifLoader *eld, unsigned char *buf, unsigned int len)
                                eld->size = 0;
                                eld->state = EL_READ_SIZE_BYTE_08;
                                break;
+                       case JPEG_MARKER_DHT:
+                       case JPEG_MARKER_DQT:
                        case JPEG_MARKER_APP0:
                        case JPEG_MARKER_APP2:
                        case JPEG_MARKER_APP13:
@@ -347,6 +360,7 @@ exif_loader_free (ExifLoader *loader)
 
        mem = loader->mem;
        exif_loader_reset (loader);
+       exif_log_unref (loader->log);
        exif_mem_free (mem, loader);
        exif_mem_unref (mem);
 }
@@ -378,7 +392,8 @@ exif_loader_get_data (ExifLoader *loader)
 {
        ExifData *ed;
 
-       if (!loader) 
+       if (!loader || (loader->data_format == EL_DATA_FORMAT_UNKNOWN) ||
+           !loader->bytes_read)
                return NULL;
 
        ed = exif_data_new_mem (loader->mem);
@@ -389,6 +404,29 @@ exif_loader_get_data (ExifLoader *loader)
 }
 
 void
+exif_loader_get_buf (ExifLoader *loader, const unsigned char **buf,
+                                                 unsigned int *buf_size)
+{
+       const unsigned char* b = NULL;
+       unsigned int s = 0;
+
+       if (loader) {
+               if (loader->data_format == EL_DATA_FORMAT_UNKNOWN) {
+                       exif_log (loader->log, EXIF_LOG_CODE_DEBUG, "ExifLoader",
+                                         "Loader format unknown");
+               } else {
+                       b = loader->buf;
+                       s = loader->bytes_read;
+               }
+       }
+
+       if (buf)
+               *buf = b;
+       if (buf_size)
+               *buf_size = s;
+}
+
+void
 exif_loader_log (ExifLoader *loader, ExifLog *log)
 {
        if (!loader)