fix: Truncated fat entries on error

src/internal/alloc.rs

@@ -83,11 +83,12 @@ impl<F> Allocator<F> {
     }
 
     fn validate(&mut self, validation: Validation) -> io::Result<()> {
-        if self.fat.len() > self.sectors.num_sectors() as usize {
+        let num_sectors = self.sectors.num_sectors() as usize;
+        if self.fat.len() > num_sectors && validation.is_strict() {
             malformed!(
                 "FAT has {} entries, but file has only {} sectors",
                 self.fat.len(),
-                self.sectors.num_sectors()
+                num_sectors
             );
         }
         for &difat_sector in self.difat_sector_ids.iter() {
@@ -133,7 +134,9 @@ impl<F> Allocator<F> {
         let mut pointees = FnvHashSet::default();
         for (from_sector, &to_sector) in self.fat.iter().enumerate() {
             if to_sector <= consts::MAX_REGULAR_SECTOR {
-                if to_sector as usize >= self.fat.len() {
+                if to_sector as usize >= self.fat.len()
+                    && validation.is_strict()
+                {
                     malformed!(
                         "FAT has {} entries, but sector {} points to {}",
                         self.fat.len(),
@@ -504,7 +507,7 @@ mod tests {
     fn pointee_out_of_range() {
         let difat = vec![0];
         let fat = vec![consts::FAT_SECTOR, 2];
-        make_allocator(difat, fat, Validation::Permissive);
+        make_allocator(difat, fat, Validation::Strict);
     }
 
     #[test]

src/internal/stream.rs

@@ -1,5 +1,5 @@
 use crate::internal::{consts, MiniAllocator, ObjType, SectorInit};
-use std::io::{self, BufRead, Read, Seek, SeekFrom, Write};
+use std::io::{self, BufRead, ErrorKind, Read, Seek, SeekFrom, Write};
 use std::sync::{Arc, RwLock, Weak};
 
 //===========================================================================//
@@ -274,6 +274,27 @@ impl<F: Read + Write + Seek> Flusher<F> for FlushBuffer {
 
 //===========================================================================//
 
+fn read_until_error<R: Read + ?Sized>(
+    this: &mut R,
+    mut buf: &mut [u8],
+) -> io::Result<usize> {
+    let mut read_amount = 0;
+
+    while !buf.is_empty() {
+        match this.read(buf) {
+            Ok(0) => break,
+            Ok(n) => {
+                buf = &mut buf[n..];
+                read_amount += n;
+            }
+            Err(err) if err.kind() == ErrorKind::Interrupted => {}
+            Err(err) => return Err(err),
+        }
+    }
+
+    Ok(read_amount)
+}
+
 fn read_data_from_stream<F: Read + Seek>(
     minialloc: &mut MiniAllocator<F>,
     stream_id: u32,
@@ -299,12 +320,14 @@ fn read_data_from_stream<F: Read + Seek>(
         if stream_len < consts::MINI_STREAM_CUTOFF as u64 {
             let mut chain = minialloc.open_mini_chain(start_sector)?;
             chain.seek(SeekFrom::Start(buf_offset_from_start))?;
-            chain.read_exact(&mut buf[..num_bytes])?;
+            return Ok(read_until_error(&mut chain, &mut buf[..num_bytes])
+                .unwrap_or(0));
         } else {
             let mut chain =
                 minialloc.open_chain(start_sector, SectorInit::Zero)?;
             chain.seek(SeekFrom::Start(buf_offset_from_start))?;
-            chain.read_exact(&mut buf[..num_bytes])?;
+            return Ok(read_until_error(&mut chain, &mut buf[..num_bytes])
+                .unwrap_or(0));
         }
     }
     Ok(num_bytes)