Handle pre-epoch file timestamps consistently and record Rust audit

crates/searchi-core/src/lib.rs

@@ -21,7 +21,6 @@ use std::{
     fs,
     path::{Path, PathBuf},
     sync::atomic::{AtomicBool, Ordering},
-    time::UNIX_EPOCH,
 };
 use walkdir::WalkDir;
 
@@ -657,12 +656,7 @@ impl SearchIndex {
                 report.discovered += 1;
                 let metadata = entry.metadata()?;
                 let size = i64::try_from(metadata.len()).context("file exceeds supported size")?;
-                let modified = metadata
-                    .modified()?
-                    .duration_since(UNIX_EPOCH)
-                    .context("file timestamp predates Unix epoch")?;
-                let mtime = i64::try_from(modified.as_nanos())
-                    .context("file timestamp exceeds supported range")?;
+                let mtime = searchi_media::unix_time_ns(metadata.modified()?)?;
                 let extension = entry
                     .path()
                     .extension()
@@ -1257,7 +1251,7 @@ impl SearchIndex {
     pub fn file_signature(&self, path: &str) -> Result<Option<(u64, i64)>> {
         self.connection
             .query_row(
-                "SELECT size,mtime FROM files WHERE path=?1 AND size>=0 AND mtime>=0",
+                "SELECT size,mtime FROM files WHERE path=?1 AND size>=0",
                 [path],
                 |row| Ok((row.get(0)?, row.get(1)?)),
             )
@@ -1294,9 +1288,8 @@ impl SearchIndex {
             Ok(value) if value.is_file() => value,
             _ => return Ok(None),
         };
-        let mtime = metadata.modified()?.duration_since(UNIX_EPOCH)?;
         let size = i64::try_from(metadata.len())?;
-        let modified = i64::try_from(mtime.as_nanos())?;
+        let modified = searchi_media::unix_time_ns(metadata.modified()?)?;
         let Some(expected_hash) = self.extracted_source_hash(path)? else {
             return Ok(None);
         };

crates/searchi-core/tests/raw_source_hash.rs

@@ -90,3 +90,40 @@ fn oversized_text_and_unsupported_files_remain_filename_only() -> Result<()> {
     assert_eq!(index.search("large.txt", 10)?.len(), 1);
     Ok(())
 }
+
+#[test]
+fn pre_epoch_source_remains_searchable_and_verifiable() -> Result<()> {
+    let directory = tempfile::tempdir()?;
+    let path = directory.path().join("archived-notes.txt");
+    let content = "Historical supplier cancellation notice\n";
+    fs::write(&path, content)?;
+    fs::File::options().write(true).open(&path)?.set_times(
+        FileTimes::new().set_modified(std::time::UNIX_EPOCH - std::time::Duration::from_secs(1)),
+    )?;
+    let mut index = SearchIndex::open(":memory:")?;
+    let report = index.index_folder(directory.path())?;
+    assert_eq!(report.indexed, 1);
+    assert_eq!(report.failures, 0);
+    assert_eq!(index.search("archived-notes.txt", 10)?.len(), 1);
+    assert_eq!(index.search("cancellation", 10)?.len(), 1);
+    let passage = index.passage_batch(0, 1)?.remove(0);
+    assert_eq!(
+        index.file_signature(&passage.path)?,
+        Some((content.len() as u64, -1_000_000_000))
+    );
+    assert_eq!(
+        index.extracted_source_hash(&passage.path)?,
+        Some(format!("{:x}", Sha256::digest(content.as_bytes())))
+    );
+    assert_eq!(
+        index
+            .source_passage(&passage.path, &passage.source, 8192)?
+            .unwrap()
+            .text,
+        content
+    );
+    let rescan = index.index_folder(directory.path())?;
+    assert_eq!(rescan.unchanged, 1);
+    assert_eq!(rescan.indexed, 0);
+    Ok(())
+}