Fixed read error with existing image data. Introduced tga_clear_error().

include/TGAImage.h

@@ -41,6 +41,7 @@ typedef struct NyTGA_Image {
 TGAError TGA_ERR;
 
 TGAError tga_error(void); /* Returns the current error, if any. */
+void tga_clear_error(void);
 TGAImage *read_tga_image(FILE *file);
 TGAImage *new_tga_image(TGAColorType type, uint8_t depth,
                         uint16_t width, uint16_t height);

src/TGADecode.c

@@ -143,7 +143,8 @@ static int _read_tga_image_data(TGAImage *image, FILE *file)
 {
     if(!_tga_sanity(image))
         goto error;
-    check(!image->data, TGA_IMAGE_IMMUTABLE_ERR, "Image data exists already.");
+    if(image->data)
+        free(image->data);
     check(file, TGA_INV_FILE_PNT, "Invalid File Pointer passed.");
     uint32_t offset = (uint32_t)TGA_HEADER_SIZE + image->_meta->id_length +
             (image->_meta->c_map_length * (image->_meta->c_map_depth/8)) +

src/TGAImage.c

@@ -287,3 +287,8 @@ TGAError tga_error()
 {
     return TGA_ERR;
 }
+
+void tga_clear_error()
+{
+    TGA_ERR = TGA_NO_ERR;
+}

src/test.c

@@ -19,10 +19,16 @@ int main(int argc, char **argv)
 
     FILE *img_file = fopen(argv[1], "rb");
     if(!img_file)
-        return 1;
+    {
+        fprintf(stderr, "Unable to open image file.\n");
+        return tga_error();
+    }
     TGAImage *img = read_tga_image(img_file);
     if(!img)
-        return 1;
+    {
+        fprintf(stderr, "Unable to read image.");
+        return tga_error();
+    }
     print_tga_data(img);
     free_tga_image(img);
     fclose(img_file);