From 2994de6d0ff53b5f728e071f2b62343be34d1cd6 Mon Sep 17 00:00:00 2001
From: "Simeon H.K. Fitch" <fitch@astraea.io>
Date: Sat, 31 Dec 2022 10:59:35 -0500
Subject: [PATCH] Changed return type of Layer::spatial_ref from `Result` to
 `Option`. Fixes #248.

---
 CHANGES.md          | 6 ++++++
 src/vector/layer.rs | 9 ++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index 27874c5b..5f5ab631 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -16,6 +16,12 @@
 
 - Added prebuilt bindings for GDAL 3.6 (released 6 November 2022).
 
+  - <https://github.com/georust/gdal/pull/352>
+
+- **Breaking**: `Layer::spatial_ref` returns `Option` instead of `Result`, thereby better reflecting the semantics documented in the [C++ API](https://gdal.org/doxygen/classOGRLayer.html#a75c06b4993f8eb76b569f37365cd19ab)
+
+  - <https://github.com/georust/gdal/pull/355>
+
 ## 0.14
 
 - Added new content to `README.md` and the root docs.
diff --git a/src/vector/layer.rs b/src/vector/layer.rs
index 7ceddee9..90065cd5 100644
--- a/src/vector/layer.rs
+++ b/src/vector/layer.rs
@@ -418,13 +418,16 @@ pub trait LayerAccess: Sized {
 
     /// Fetch the spatial reference system for this layer.
     ///
+    /// Returns `Some(SpatialRef)`, or `None` if one isn't defined.
+    ///
     /// Refer [OGR_L_GetSpatialRef](https://gdal.org/doxygen/classOGRLayer.html#a75c06b4993f8eb76b569f37365cd19ab)
-    fn spatial_ref(&self) -> Result<SpatialRef> {
+    fn spatial_ref(&self) -> Option<SpatialRef> {
         let c_obj = unsafe { gdal_sys::OGR_L_GetSpatialRef(self.c_layer()) };
         if c_obj.is_null() {
-            return Err(_last_null_pointer_err("OGR_L_GetSpatialRef"));
+            None
+        } else {
+            unsafe { SpatialRef::from_c_obj(c_obj) }.ok()
         }
-        unsafe { SpatialRef::from_c_obj(c_obj) }
     }
 
     fn reset_feature_reading(&mut self) {