test(pty): trace Windows Unicode parser crash

Author: jlongster

.github/workflows/windows.yml

@@ -75,6 +75,20 @@ jobs:
         if: failure() && steps.tests.outcome == 'failure'
         timeout-minutes: 10
         run: cargo test --locked --lib --all-features -- --test-threads=1 --nocapture
+      - name: Debug Windows parser crash
+        if: failure() && steps.tests.outcome == 'failure'
+        timeout-minutes: 10
+        run: |
+          $artifacts = cargo test --locked --lib --no-run --message-format=json | ForEach-Object { $_ | ConvertFrom-Json }
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+          $binary = ($artifacts | Where-Object { $_.reason -eq 'compiler-artifact' -and $_.profile.test -and $_.executable }).executable
+          $debugger = 'C:\Program Files\LLVM\bin\lldb.exe'
+          if (Test-Path $debugger) {
+            & $debugger --batch -o run -o 'thread backtrace all' -o 'register read' -- $binary --exact service::tests::rows_keep_physical_wraps_and_unicode_graphemes --nocapture
+          } else {
+            Write-Output 'LLDB is unavailable; checking installed Windows SDK debuggers'
+            Get-ChildItem 'C:\Program Files (x86)\Windows Kits\10\Debuggers' -Filter cdb.exe -Recurse -ErrorAction SilentlyContinue
+          }
       - name: Smoke test executable
         if: ${{ !cancelled() && steps.build.outcome == 'success' }}
         run: |

src/service.rs

@@ -1434,7 +1434,9 @@ mod tests {
             max_scrollback: 2 * 1024 * 1024,
         })
         .unwrap();
+        eprintln!("rows_terminal: writing {} bytes", input.len());
         terminal.vt_write(input.as_bytes());
+        eprintln!("rows_terminal: write complete");
         terminal
     }
 
@@ -1474,13 +1476,16 @@ mod tests {
 
     #[test]
     fn rows_keep_physical_wraps_and_unicode_graphemes() {
+        eprintln!("unicode rows: ASCII setup");
         let terminal = rows_terminal(4, 3, "abcdefghij");
         assert_eq!(
             format_rows(&terminal, None).unwrap(),
             ["abcd", "efgh", "ij"]
         );
         assert_eq!(format_rows(&terminal, Some(2)).unwrap(), ["efgh", "ij"]);
+        eprintln!("unicode rows: Unicode setup");
         let terminal = rows_terminal(4, 3, "a\u{301}\u{754c}bc");
+        eprintln!("unicode rows: formatting");
         assert_eq!(
             format_rows(&terminal, None).unwrap(),
             ["a\u{301}\u{754c}b", "c", ""]