- ignore missing colormap

.gitignore

@@ -1,5 +1,6 @@
-
 /target/
 **/*.rs.bk
 Cargo.lock
 tests/benches/corpus/
+.idea
+.agentbridge

src/decoder/image.rs

@@ -467,11 +467,11 @@ impl Image {
                     }
                     Some(map)
                 }
-                None => {
-                    return Err(TiffError::FormatError(
-                        TiffFormatError::RequiredTagNotFound(Tag::ColorMap),
-                    ));
-                }
+                // A missing palette is not an error. The pixel values of an indexed image are just
+                // indices into the palette, and the palette itself is only display information, so
+                // the image still decodes. Callers observe the absence as `None` from
+                // `Decoder::color_map`.
+                None => None,
             }
         } else {
             None

src/directory.rs

@@ -171,7 +171,7 @@ mod tests {
             dir.get(Tag::Unknown(1))
                 .expect("tag 1 should be present after this chain")
                 .count(),
-            u16::MAX.into()
+            u64::from(u16::MAX)
         );
     }