imageio: do not fail in saving an image if no metadata is available

(cherry picked from commit 86d48be88b6f9fe36e5e25185ec4fda7696efc25)

rtengine/imageio.cc

@@ -41,6 +41,7 @@
 #include "iccjpeg.h"
 #include "color.h"
 #include "imagedata.h"
+#include "settings.h"
 
 #include "jpeg.h"
 
@@ -48,6 +49,8 @@ using namespace std;
 using namespace rtengine;
 using namespace rtengine::procparams;
 
+namespace rtengine { extern const Settings *settings; }
+
 namespace
 {
 
@@ -1355,8 +1358,18 @@ bool ImageIO::saveMetadata(const Glib::ustring &fname) const
         return true;
     }
 
+    bool has_meta = true;
     try {
         metadataInfo.load();
+    } catch (const std::exception& exc) {
+        if (settings->verbose) {
+            std::cout << "EXIF LOAD ERROR: " << exc.what() << std::endl;
+        }
+        has_meta = false;
+    }
+
+    if (has_meta) {
+        try {
             metadataInfo.saveToImage(fname);
             // auto src = open_exiv2(metadataInfo.filename());
             // auto dst = open_exiv2(fname);
@@ -1384,9 +1397,11 @@ bool ImageIO::saveMetadata(const Glib::ustring &fname) const
             //     }
             // }
             // dst->writeMetadata();
-        return true;
         } catch (const std::exception& exc) {
             std::cout << "EXIF ERROR: " << exc.what() << std::endl;
             return false;
         }
+    }
+
+    return true;
 }