read.c: Clamp CICP enum values to valid range

If invalid values are seen, replace them with UNSPECIFIED. This
change does not affect the color conversion paths in anyway, it just
changes what is reported in the public API.

src/read.c

@@ -2222,9 +2222,20 @@ static avifBool avifParseColourInformationBox(avifProperty * prop, uint64_t rawO
         colr->iccOffset = rawOffset + avifROStreamOffset(&s);
         colr->iccSize = avifROStreamRemainingBytes(&s);
     } else if (!memcmp(colorType, "nclx", 4)) {
-        AVIF_CHECK(avifROStreamReadU16(&s, &colr->colorPrimaries));          // unsigned int(16) colour_primaries;
+        AVIF_CHECK(avifROStreamReadU16(&s, &colr->colorPrimaries)); // unsigned int(16) colour_primaries;
+        if (colr->colorPrimaries == 3 ||
+            (colr->colorPrimaries > AVIF_COLOR_PRIMARIES_DCI_P3 && colr->colorPrimaries < AVIF_COLOR_PRIMARIES_EBU3213) ||
+            colr->colorPrimaries > AVIF_COLOR_PRIMARIES_EBU3213) {
+            colr->colorPrimaries = AVIF_COLOR_PRIMARIES_UNSPECIFIED;
+        }
         AVIF_CHECK(avifROStreamReadU16(&s, &colr->transferCharacteristics)); // unsigned int(16) transfer_characteristics;
-        AVIF_CHECK(avifROStreamReadU16(&s, &colr->matrixCoefficients));      // unsigned int(16) matrix_coefficients;
+        if (colr->transferCharacteristics == 3 || colr->transferCharacteristics > AVIF_TRANSFER_CHARACTERISTICS_HLG) {
+            colr->transferCharacteristics = AVIF_TRANSFER_CHARACTERISTICS_UNSPECIFIED;
+        }
+        AVIF_CHECK(avifROStreamReadU16(&s, &colr->matrixCoefficients)); // unsigned int(16) matrix_coefficients;
+        if (colr->matrixCoefficients == 3 || colr->matrixCoefficients >= AVIF_MATRIX_COEFFICIENTS_LAST) {
+            colr->matrixCoefficients = AVIF_MATRIX_COEFFICIENTS_UNSPECIFIED;
+        }
         uint8_t full_range_flag;
         AVIF_CHECK(avifROStreamReadBits8(&s, &full_range_flag, /*bitCount=*/1)); // unsigned int(1) full_range_flag;
         colr->range = full_range_flag ? AVIF_RANGE_FULL : AVIF_RANGE_LIMITED;