feat: upgrade version when reading when needed

Allows for more permissive reading

Cargo.toml

@@ -15,10 +15,11 @@ edition = "2021"
 [dependencies]
 byteorder = "1.4"
 chrono = "0.4"
+laz = { version = "0.9.1", optional = true }
+log = "0.4"
 num-traits = "0.2"
 thiserror = "1.0"
 uuid = "1"
-laz = { version = "0.9.1", optional = true }
 
 [dev-dependencies]
 criterion = "0.5"

src/header/builder.rs

@@ -249,6 +249,28 @@ impl Builder {
         };
         Ok(header)
     }
+
+    /// Returns the minimum supported version for this builder, as determined by its features.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use las::{Builder, Version};
+    ///
+    /// assert_eq!(Builder::default().minimum_supported_version().unwrap(), Version::new(1, 0));
+    /// ```
+    pub fn minimum_supported_version(&self) -> Option<Version> {
+        // TODO can we make a validity check that doesn't involve a full
+        // conversion into a header, without duplicating a lot of logic?
+        for minor in [0, 1, 2, 3, 4] {
+            let mut builder = self.clone();
+            builder.version.minor = minor;
+            if builder.into_header().is_ok() {
+                return Some(Version::new(1, minor));
+            }
+        }
+        None
+    }
 }
 
 impl<V: Into<Version>> From<V> for Builder {

src/reader.rs

@@ -302,6 +302,16 @@ impl<'a> Reader<'a> {
 
         let _ = read.seek(SeekFrom::Start(offset_to_point_data))?;
 
+        if let Some(version) = builder.minimum_supported_version() {
+            if version > builder.version {
+                log::warn!(
+                    "upgrading las version to {} (from {})",
+                    version,
+                    builder.version
+                );
+                builder.version = version;
+            }
+        }
         let header = builder.into_header()?;
 
         #[cfg(feature = "laz")]

tests/permissive_reading.rs

@@ -0,0 +1,9 @@
+#[test]
+#[cfg(feature = "laz")]
+fn read_invalid_file() {
+    // https://github.com/gadomski/las-rs/pull/61
+    use las::Read;
+
+    let mut reader = las::Reader::from_path("tests/data/32-1-472-150-76.laz").unwrap();
+    let _ = reader.points().next().unwrap().unwrap();
+}