api: add OIIO_NODISCARD_ERROR to tiffutils.h

src/include/OpenImageIO/tiffutils.h

@@ -181,8 +181,8 @@ tiff_dir_data (const TIFFDirEntry &td, cspan<uint8_t> data);
 /// ImageSpec.  Return true if all is ok, false if the exif block was
 /// somehow malformed.  The binary data pointed to by 'exif' should
 /// start with a TIFF directory header.
-OIIO_API bool decode_exif (cspan<uint8_t> exif, ImageSpec &spec);
-OIIO_API bool decode_exif (string_view exif, ImageSpec &spec);
+OIIO_NODISCARD_ERROR OIIO_API bool decode_exif (cspan<uint8_t> exif, ImageSpec &spec);
+OIIO_NODISCARD_ERROR OIIO_API bool decode_exif (string_view exif, ImageSpec &spec);
 
 /// Construct an Exif data block from the ImageSpec, appending the Exif
 /// data as a big blob to the char vector. Endianness can be specified with
@@ -193,13 +193,13 @@ OIIO_API void encode_exif (const ImageSpec &spec, std::vector<char> &blob,
 /// Helper: For the given OIIO metadata attribute name, look up the Exif tag
 /// ID, TIFFDataType (expressed as an int), and count. Return true and fill
 /// in the fields if found, return false if not found.
-OIIO_API bool exif_tag_lookup (string_view name, int &tag,
+OIIO_NODISCARD_ERROR OIIO_API bool exif_tag_lookup (string_view name, int &tag,
                                int &tifftype, int &count);
 
 /// Helper: For the given OIIO metadata attribute name, look up the GPS tag
 /// ID, TIFFDataType (expressed as an int), and count. Return true and fill
 /// in the fields if found, return false if not found.
-OIIO_API bool gps_tag_lookup (string_view name, int &tag,
+OIIO_NODISCARD_ERROR OIIO_API bool gps_tag_lookup (string_view name, int &tag,
                               int &tifftype, int &count);
 
 /// Add metadata to spec based on raw IPTC (International Press
@@ -210,10 +210,10 @@ OIIO_API bool gps_tag_lookup (string_view name, int &tag,
 /// metadata without having to duplicate functionality within each
 /// plugin.  Note that IIM is actually considered obsolete and is
 /// replaced by an XML scheme called XMP.
-OIIO_API bool decode_iptc_iim (string_view iptc, ImageSpec &spec);
+OIIO_NODISCARD_ERROR OIIO_API bool decode_iptc_iim (string_view iptc, ImageSpec &spec);
 
 // DEPRECATED(3.2) -- unsafe version
-OIIO_API bool decode_iptc_iim (const void *iptc, int length, ImageSpec &spec);
+OIIO_NODISCARD_ERROR OIIO_API bool decode_iptc_iim (const void *iptc, int length, ImageSpec &spec);
 
 /// Find all the IPTC-amenable metadata in spec and assemble it into an
 /// IIM data block in iptc.  This is a utility function to make it easy
@@ -222,14 +222,14 @@ OIIO_API bool decode_iptc_iim (const void *iptc, int length, ImageSpec &spec);
 /// that IIM is actually considered obsolete and is replaced by an XML
 /// scheme called XMP. Return true if it was successful and any items
 /// were encoded.
-OIIO_API bool encode_iptc_iim (const ImageSpec &spec, std::vector<char> &iptc);
+OIIO_NODISCARD_ERROR OIIO_API bool encode_iptc_iim (const ImageSpec &spec, std::vector<char> &iptc);
 
 /// Add metadata to spec based on XMP data in an XML block.  Return true
 /// if all is ok, false if the xml was somehow malformed.  This is a
 /// utility function to make it easy for multiple format plugins to
 /// support embedding XMP metadata without having to duplicate
 /// functionality within each plugin.
-OIIO_API bool decode_xmp (cspan<uint8_t> xml, ImageSpec &spec);
+OIIO_NODISCARD_ERROR OIIO_API bool decode_xmp (cspan<uint8_t> xml, ImageSpec &spec);
 OIIO_API bool decode_xmp (string_view xml, ImageSpec &spec);
 
 /// Find all the relevant metadata (IPTC, Exif, etc.) in spec and
@@ -246,7 +246,7 @@ OIIO_API std::string encode_xmp (const ImageSpec &spec, bool minimal=false);
 /// the contents of `error` to something useful).  This is a utility function
 /// to make it easy for multiple format plugins to support embedding ICC
 /// metadata without having to duplicate functionality within each plugin.
-OIIO_API bool decode_icc_profile(cspan<uint8_t> iccdata, ImageSpec& spec,
+OIIO_NODISCARD_ERROR OIIO_API bool decode_icc_profile(cspan<uint8_t> iccdata, ImageSpec& spec,
                                  std::string& error);
 
 

src/jpeg.imageio/jpeginput.cpp

@@ -296,8 +296,13 @@ JpgInput::open(const std::string& name, ImageSpec& newspec)
         if (is_exif_marker(m)) {
             // The block starts with "Exif\0\0", so skip 6 bytes to get
             // to the start of the actual Exif data TIFF directory
-            decode_exif(string_view((char*)m->data + 6, m->data_length - 6),
-                        m_spec);
+            bool ok = decode_exif(string_view((char*)m->data + 6,
+                                              m->data_length - 6),
+                                  m_spec);
+            if (!ok && OIIO::get_int_attribute("imageinput:strict")) {
+                errorfmt("Could not decode Exif data in JPEG file");
+                return false;
+            }
         } else if (m->marker == (JPEG_APP0 + 1) && m->data_length >= 28
                    && !strncmp((const char*)m->data,
                                "http://ns.adobe.com/xap/1.0/", 28)) {  //NOSONAR

src/png.imageio/png_pvt.h

@@ -171,7 +171,7 @@ decode_png_text_exif(string_view raw, ImageSpec& spec)
         raw.remove_prefix(2);
     }
     if (Strutil::istarts_with(decoded, "Exif")) {
-        decode_exif(decoded, spec);
+        return decode_exif(decoded, spec);
     }
     return false;
 }
@@ -345,7 +345,14 @@ read_info(png_structp& sp, png_infop& ip, int& bit_depth, int& color_type,
     png_uint_32 num_exif = 0;
     png_bytep exif_data  = nullptr;
     if (png_get_eXIf_1(sp, ip, &num_exif, &exif_data)) {
-        decode_exif(cspan<uint8_t>(exif_data, span_size_t(num_exif)), spec);
+        bool ok = decode_exif(cspan<uint8_t>(exif_data, span_size_t(num_exif)),
+                              spec);
+        if (!ok) {
+            ImageInput* pnginput = (ImageInput*)png_get_io_ptr(sp);
+            if (pnginput)
+                pnginput->errorfmt(
+                    "Could not decode Exif metadata from PNG eXIf chunk");
+        }
     }
 #endif
 

src/tiff.imageio/tiffinput.cpp

@@ -1509,7 +1509,10 @@ TIFFInput::readspec(bool read_meta)
         } else {
             iptc.assign(iptcdata, iptcdata + iptcsize);
         }
-        decode_iptc_iim(&iptc[0], iptcsize, m_spec);
+        bool ok = decode_iptc_iim(&iptc[0], iptcsize, m_spec);
+        if (!ok && OIIO::get_int_attribute("imageinput:strict")) {
+            errorfmt("Could not decode IPTC metadata in TIFF file");
+        }
     }
 
     // Search for an XML packet containing XMP (IPTC, Exif, etc.)

src/tiff.imageio/tiffoutput.cpp

@@ -934,7 +934,10 @@ TIFFOutput::open(const std::string& name, const ImageSpec& userspec,
         // was because of a size mixup on our part that has since been fixed.
         // Should we re-enable it by default in the future?
         std::vector<char> iptc;
-        encode_iptc_iim(m_spec, iptc);
+        bool iptc_ok = encode_iptc_iim(m_spec, iptc);
+        if (!iptc_ok) {
+            errorfmt("Failed to encode IPTC metadata for writing");
+        }
         if (iptc.size()) {
             TIFFSetField(m_tif, TIFFTAG_RICHTIFFIPTC, iptc.size(), &iptc[0]);
         }

src/webp.imageio/webpinput.cpp

@@ -195,9 +195,14 @@ WebpInput::open(const std::string& name, ImageSpec& spec,
     if (m_demux_flags & EXIF_FLAG
         && WebPDemuxGetChunk(m_demux, "EXIF", 1, &chunk_iter)) {
         cspan<uint8_t> exif_span(chunk_iter.chunk.bytes, chunk_iter.chunk.size);
+        bool ok = true;
         if (webp_exif_payload_has_tiff_header(exif_span))
-            decode_exif(exif_span, m_spec);
+            ok = decode_exif(exif_span, m_spec);
         WebPDemuxReleaseChunkIterator(&chunk_iter);
+        if (!ok && OIIO::get_int_attribute("imageinput:strict")) {
+            errorfmt("Possible corrupt file, could not decode EXIF metadata");
+            return false;
+        }
     }
     if (m_demux_flags & XMP_FLAG
         && WebPDemuxGetChunk(m_demux, "XMP ", 1, &chunk_iter)) {