dont panic when parsing invalid displacement neighbours

src/data/displacement.rs

@@ -1,4 +1,5 @@
 use super::vector::Vector;
+use crate::error::InvalidNeighbourError;
 use binrw::{BinRead, BinResult, ReadOptions};
 use bitflags::bitflags;
 use num_enum::TryFromPrimitive;
@@ -75,7 +76,6 @@ impl BinRead for DisplacementNeighbour {
 static_assertions::const_assert_eq!(size_of::<DisplacementNeighbour>(), 12);
 
 #[derive(Debug, Clone, BinRead)]
-#[br(assert(neighbour_index == u16::MAX || (neighbour_orientation < 4 && span < 4 && neighbour_span < 4), "valid neighbour index with invalid enum fields"))]
 struct RawDisplacementSubNeighbour {
     neighbour_index: u16,
     neighbour_orientation: u8,
@@ -101,18 +101,24 @@ pub struct DisplacementSubNeighbour {
 }
 
 impl TryFrom<RawDisplacementSubNeighbour> for DisplacementSubNeighbour {
-    type Error = ();
+    type Error = InvalidNeighbourError;
 
     fn try_from(value: RawDisplacementSubNeighbour) -> Result<Self, Self::Error> {
         match value.neighbour_index {
-            u16::MAX => Err(()),
+            u16::MAX => Err(InvalidNeighbourError::InvalidNeighbourIndex),
             neighbour_index => Ok(DisplacementSubNeighbour {
                 neighbour_index,
-                // note that we already checked if these enums are valid in the assert of the RawDisplacementSubNeighbour reader
                 neighbour_orientation: NeighbourOrientation::try_from(value.neighbour_orientation)
-                    .unwrap(),
-                span: NeighbourSpan::try_from(value.span).unwrap(),
-                neighbour_span: NeighbourSpan::try_from(value.neighbour_span).unwrap(),
+                    .map_err(|_| {
+                        InvalidNeighbourError::InvalidNeighbourOrientation(
+                            value.neighbour_orientation,
+                        )
+                    })?,
+                span: NeighbourSpan::try_from(value.span)
+                    .map_err(|_| InvalidNeighbourError::InvalidNeighbourSpan(value.span))?,
+                neighbour_span: NeighbourSpan::try_from(value.neighbour_span).map_err(|_| {
+                    InvalidNeighbourError::InvalidNeighbourSpan(value.neighbour_span)
+                })?,
             }),
         }
     }

src/data/mod.rs

@@ -32,7 +32,6 @@ where
 {
     use binrw::BinReaderExt;
     use std::any::type_name;
-    use std::io::Cursor;
 
     let bytes = [0; 512];
     let mut reader = Cursor::new(bytes);

src/error.rs

@@ -1,8 +1,8 @@
+use crate::bspfile::LumpType;
 use crate::data::*;
 use std::num::{ParseFloatError, ParseIntError};
 use thiserror::Error;
 use zip::result::ZipError;
-use crate::bspfile::LumpType;
 
 #[non_exhaustive]
 #[derive(Debug, Error)]
@@ -105,6 +105,18 @@ pub enum ValidationError {
     NonSquareDisplacement(i16),
     #[error("No static prop lump found")]
     NoStaticPropLump,
+    #[error(transparent)]
+    Neighbour(InvalidNeighbourError),
+}
+
+#[derive(Debug, Error)]
+pub enum InvalidNeighbourError {
+    #[error("Invalid neighbour span")]
+    InvalidNeighbourIndex,
+    #[error("Invalid neighbour span")]
+    InvalidNeighbourSpan(u8),
+    #[error("Invalid neighbour orientation")]
+    InvalidNeighbourOrientation(u8),
 }
 
 #[derive(Debug, Error)]

src/handle/mod.rs

@@ -122,7 +122,10 @@ impl<'a> Handle<'a, Leaf> {
 
 impl<'a> Handle<'a, TextureInfo> {
     pub fn texture_data(&self) -> Handle<'a, TextureData> {
-        Handle::new(self.bsp, &self.bsp.textures_data[self.data.texture_data_index as usize])
+        Handle::new(
+            self.bsp,
+            &self.bsp.textures_data[self.data.texture_data_index as usize],
+        )
     }
     pub fn name(&self) -> &'a str {
         self.texture_data().name()
@@ -139,4 +142,4 @@ impl<'a> Handle<'a, TextureData> {
             part
         }
     }
-}
+}

src/lib.rs

@@ -16,8 +16,8 @@ use bspfile::BspFile;
 pub use error::{BspError, StringError};
 use lzma_rs::decompress::{Options, UnpackedSize};
 use reader::LumpReader;
-use std::{io::Read, ops::Deref};
 use std::cmp::min;
+use std::{io::Read, ops::Deref};
 
 pub type BspResult<T> = Result<T, BspError>;
 
@@ -197,9 +197,12 @@ impl Bsp {
         let texture_string_tables = bsp_file
             .lump_reader(LumpType::TextureDataStringTable)?
             .read_vec(|r| r.read())?;
-        let texture_string_data = String::from_utf8(bsp_file
-            .get_lump(LumpType::TextureDataStringData)?
-            .into_owned()).map_err(|e| BspError::String(StringError::NonUTF8(e.utf8_error())))?;
+        let texture_string_data = String::from_utf8(
+            bsp_file
+                .get_lump(LumpType::TextureDataStringData)?
+                .into_owned(),
+        )
+        .map_err(|e| BspError::String(StringError::NonUTF8(e.utf8_error())))?;
         let planes = bsp_file
             .lump_reader(LumpType::Planes)?
             .read_vec(|r| r.read())?;
@@ -449,9 +452,7 @@ impl Bsp {
             "texture_string_tables",
         )?;
         self.validate_indexes(
-            self.texture_string_tables
-                .iter()
-                .map(|texture| *texture),
+            self.texture_string_tables.iter().map(|texture| *texture),
             &self.texture_string_data.as_bytes(),
             "texture_string_tables",
             "texture_string_data",