From 6c4323b50b53d74411c0fd852b0d6225399023c9 Mon Sep 17 00:00:00 2001
From: Dan Schafer <dan.schafer@gmail.com>
Date: Tue, 28 Jul 2026 19:13:39 -0700
Subject: [PATCH] Harden CLI input and terminal handling

Use image::ImageFormat::from_path for automatic input dispatch and restore the terminal cursor if animated output fails.
---
 CHANGELOG.md               |  5 +++++
 src/main.rs                | 15 ++++++++++++---
 tests/command_line_runs.rs | 19 +++++++++++++++++++
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5e634ff..4158332 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,12 +17,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   [#15](https://github.com/dschafer/qsolve/issues/15) to be solved without
   forcing chains.
 
+### Changed
+
+- Make `--file-type=auto` use recognized image extensions to select image parsing.
+
 ### Fixed
 
 - Give out-of-range values passed to bitset-backed sets consistent, descriptive panics.
 - Return an error instead of panicking when an image contains no detectable grid.
 - Calculate queen and X pixel ratios against the inspected image area.
 - Preserve spaces used as blank markers at the edges of partial-state grids.
+- Restore the terminal cursor when animation exits with an error.
 
 ## [1.0.0] - 2025-04-23
 
diff --git a/src/main.rs b/src/main.rs
index 89647fa..46ae672 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -157,9 +157,9 @@ fn queens_file_from_path(path_args: &PathCli) -> Result<QueensFile> {
         #[cfg(feature = "image")]
         FileType::Image => QueensFile::try_from_image_file(&path_args.path),
         #[cfg(feature = "image")]
-        FileType::Auto => QueensFile::try_from_text_file(&path_args.path)
-            .or_else(|_| QueensFile::try_from_image_file(&path_args.path)),
-        #[cfg(not(feature = "image"))]
+        FileType::Auto if image::ImageFormat::from_path(&path_args.path).is_ok() => {
+            QueensFile::try_from_image_file(&path_args.path)
+        }
         FileType::Auto => QueensFile::try_from_text_file(&path_args.path),
     }?;
     if path_args.clear {
@@ -245,6 +245,14 @@ fn print_animated_iter_item(
     Ok(())
 }
 
+struct CursorGuard;
+
+impl Drop for CursorGuard {
+    fn drop(&mut self) {
+        let _ = execute!(std::io::stdout(), Show);
+    }
+}
+
 /// Top-level entry point for the animate subcommand.
 fn animate(
     path_args: &PathCli,
@@ -262,6 +270,7 @@ fn animate(
         let _ = execute!(std::io::stdout(), Show);
         std::process::exit(130);
     })?;
+    let _cursor_guard = CursorGuard;
     execute!(stdout, Hide)?;
 
     for solve_iter_item in solve_iter(solve_state, solve_args.strategy, &heuristics) {
diff --git a/tests/command_line_runs.rs b/tests/command_line_runs.rs
index bb8899d..da221ad 100644
--- a/tests/command_line_runs.rs
+++ b/tests/command_line_runs.rs
@@ -1,4 +1,6 @@
 use assert_cmd::prelude::*;
+#[cfg(feature = "image")]
+use std::fs;
 use std::process::Command;
 
 #[test]
@@ -44,6 +46,23 @@ fn print_fails_on_bad_file() -> Result<(), Box<dyn std::error::Error>> {
     Ok(())
 }
 
+#[cfg(feature = "image")]
+#[test]
+fn auto_uses_extension_to_select_parser() -> Result<(), Box<dyn std::error::Error>> {
+    let path = std::env::temp_dir().join(format!(
+        "qsolve-text-with-image-extension-{}.png",
+        std::process::id()
+    ));
+    fs::write(&path, "wwww\nwkkk\nrrrr\nbbbb")?;
+
+    let mut cmd = Command::cargo_bin("qsolve")?;
+    cmd.arg("print").arg(&path);
+    cmd.assert().failure();
+
+    fs::remove_file(path)?;
+    Ok(())
+}
+
 #[cfg(feature = "image")]
 #[test]
 fn print_accepts_image_file_type() -> Result<(), Box<dyn std::error::Error>> {