Merge branch 'master' into fix-binary-detection-across-lines-3554

CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ## Features
 
+- Add `-b` / `--number-nonblank` flag to only number non-blank lines, for `cat -b` compatibility. Closes #3856, see #3857 (@MeGaurav4)
 - Add a `--sanitize=<auto|always|never>` flag for safe display of untrusted input. It implies `--strip-ansi` at the same value and additionally substitutes terminal-active control bytes (cursor moves, charset switches, beep, etc.) and Unicode bidi / zero-width formatting characters with the Unicode replacement character (U+FFFD). Mitigates Trojan-Source-style spoofing (CVE-2021-42574). See #3729 (@curious-rabbit)
 - Map justfile, Justfile, .justfile, and *.justfile to Makefile syntax highlighting, see #3623 (@zachvalenta)
 - Preserve `--diff` change markers and snip separators when `--plain` is set. Closes #3630, see #3643 (@mvanhorn)
@@ -25,6 +26,9 @@
 
 ## Bugfixes
 - Detect binary content beyond the first line, preventing encrypted files with early line breaks from being treated as text. Closes #3554, see #3877 (@Matei02355)
+- Use the last occurrence of numbering and plain flags in combined short arguments, see #3897 (@cuishuang)
+- Avoid a spurious Cargo manifest error during installation from Git, see #3899 (@rootsec1)
+- Avoid repeated scans of long lines in Log syntax highlighting, see #3876 (@Matei02355)
 - Fix `--list-languages` respecting `--paging=never`, see #3828 (@cyphercodes)
 - Fix `--sanitize` passing through the bidi control characters U+200E, U+200F and U+061C, see #3862 (@lenamonj)
 - `--strip-ansi`: also strip 8-bit C1 introducers (U+0090, U+0098, U+009B, U+009D, U+009E, U+009F) and DCS/SOS/PM/APC sequence bodies, which previously passed through. See #3729 (@curious-rabbit)

Cargo.lock

@@ -281,9 +281,9 @@ checksum = "1e748733b7cbc798e1434b6ac524f0c1ff2ab456fe201501e6497c8417a4fc33"
 
 [[package]]
 name = "bytesize"
-version = "2.4.2"
+version = "2.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d7c8918969267b2932ffd5655509bbbea0833823058c378876953217f5fc50e"
+checksum = "7354288c522e7e980fafd2075d63d1285794c3a6a16cdd492f189ea406e5f18b"
 
 [[package]]
 name = "cc"
@@ -362,9 +362,9 @@ checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
 
 [[package]]
 name = "console"
-version = "0.16.3"
+version = "0.16.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d64e8af5551369d19cf50138de61f1c42074ab970f74e99be916646777f8fc87"
+checksum = "4fe5f465a4f6fee88fad41b85d990f84c835335e85b5d9e6e63e0d06d28cba7c"
 dependencies = [
  "encode_unicode",
  "libc",
@@ -1604,9 +1604,9 @@ checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
 
 [[package]]
 name = "globset"
-version = "0.4.18"
+version = "0.4.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52dfc19153a48bde0cbd630453615c8151bce3a5adfac7a0aebfbf0a1e1f57e3"
+checksum = "07c34a9410465b45bd9787443bc7370f37735bad04b0f0cd57ff1a3186c98988"
 dependencies = [
  "aho-corasick",
  "bstr",
@@ -1705,9 +1705,9 @@ checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 
 [[package]]
 name = "indexmap"
-version = "2.14.0"
+version = "2.14.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
+checksum = "07aa2048142242915a31d35844fb311e0e53fcca590c3a0a40dcf1b841fa09eb"
 dependencies = [
  "equivalent",
  "hashbrown 0.17.1",
@@ -2196,9 +2196,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.16"
+version = "0.4.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8fcfdb36bda0c880c5931cdc7a2bcdc8ba4556847b9d912bca70bc94708711ad"
+checksum = "ad8553b9b26413251cbf30e620595c7a41b3887f03da04579c0e6b0d6a06b4b2"
 dependencies = [
  "aho-corasick",
  "memchr",

README.md

@@ -902,7 +902,7 @@ cargo install --path . --locked --force
 ```
 
 If you want to build an application that uses `bat`'s pretty-printing
-features as a library, check out the [the API documentation](https://docs.rs/bat/).
+features as a library, check out the [API documentation](https://docs.rs/bat/).
 Note that you have to use either `regex-onig` or `regex-fancy` as a feature
 when you depend on `bat` as a library.
 

assets/syntaxes/02_Extra/log.sublime-syntax

@@ -38,22 +38,41 @@ contexts:
       scope: markup.underline.link.scheme.log
       push: url-host
   log_level_lines:
-    - match: (?=.*{{error}})
+    # Prevent retrying each lookahead at every position.
+    - match: ^(?=.*{{error}})
       push:
         - error_line_meta
         - main_pop_at_eol
-    - match: (?=.*{{warning}})
+    - match: ^(?=.*{{warning}})
       push:
         - warning_line_meta
         - main_pop_at_eol
-    - match: (?=.*{{info}})
+    - match: ^(?=.*{{info}})
       push:
         - info_line_meta
         - main_pop_at_eol
-    - match: (?=.*{{debug}})
+    - match: ^(?=.*{{debug}})
       push:
         - debug_line_meta
         - main_pop_at_eol
+  # For syntaxes that embed Log after consuming a prefix. Call this context once.
+  log_level_lines_at_current_position:
+    - match: (?=.*{{error}})
+      set:
+        - error_line_meta
+        - main_pop_at_eol
+    - match: (?=.*{{warning}})
+      set:
+        - warning_line_meta
+        - main_pop_at_eol
+    - match: (?=.*{{info}})
+      set:
+        - info_line_meta
+        - main_pop_at_eol
+    - match: (?=.*{{debug}})
+      set:
+        - debug_line_meta
+        - main_pop_at_eol
   log_levels:
     - match: '{{error}}'
       scope: markup.error.log

assets/syntaxes/02_Extra/syslog.sublime-syntax

@@ -50,6 +50,17 @@ contexts:
     - match: (?=\])
       pop: true
   text:
+    - include: text_special
+    - match: ''
+      set: classify_log_text
+  classify_log_text:
+    - include: scope:text.log#log_level_lines_at_current_position
+    - match: ''
+      set: text_body
+  text_body:
+    - include: text_special
+    - include: scope:text.log
+  text_special:
     - match: $
       pop: true
     - match: '<\w+>'
@@ -62,4 +73,3 @@ contexts:
       escape: \)$
       escape_captures:
         0: punctuation.section.block.end.syslog
-    - include: scope:text.log

doc/long-help.txt

@@ -83,6 +83,16 @@ Options:
   -n, --number
           Only show line numbers, no other decorations. This is an alias for '--style=numbers'
 
+  -b, --number-nonblank
+          Only show line numbers for non-blank lines, no other decorations. This is an alias for
+          '--style=numbers'. Non-blank lines are lines that contain any character before the line
+          ending, including spaces and tabs. When used together with --number (-n),
+          --number-nonblank (-b) takes precedence.
+          
+          Example:
+            printf 'alpha\n\nbeta\n' | bat -b
+            numbers 'alpha' and 'beta', but skips the empty line.
+
       --color <when>
           Specify when to use colored output. The automatic mode only enables colors if an
           interactive terminal is detected - colors are automatically disabled if the output goes to

doc/short-help.txt

@@ -33,6 +33,8 @@ Options:
           Truncate all lines longer than screen width. Alias for '--wrap=never'.
   -n, --number
           Show line numbers (alias for '--style=numbers').
+  -b, --number-nonblank
+          Show line numbers for non-blank lines only (alias for '--style=numbers').
       --color <when>
           When to use colors (*auto*, never, always).
       --italic-text <when>

src/assets.rs

@@ -363,11 +363,11 @@ impl HighlightingAssets {
         reader: &mut InputReader,
     ) -> Result<Option<SyntaxReferenceInSet<'_>>> {
         let syntax_set = self.get_syntax_set()?;
-        Ok(String::from_utf8(reader.first_line.clone())
+        Ok(std::str::from_utf8(&reader.first_line)
             .ok()
             .and_then(|l| {
                 // Strip UTF-8 BOM if present
-                let line = l.strip_prefix('\u{feff}').unwrap_or(&l);
+                let line = l.strip_prefix('\u{feff}').unwrap_or(l);
                 syntax_set.find_syntax_by_first_line(line)
             })
             .map(|syntax| SyntaxReferenceInSet { syntax, syntax_set }))

src/bin/bat/app.rs

@@ -59,6 +59,10 @@ pub struct App {
     /// (not from config file or environment variables).
     /// This is used to honor the flag when piping output, similar to `cat -n`.
     number_from_cli: bool,
+    /// True if -b / --number-nonblank was passed on the command line
+    /// (not from config file or environment variables).
+    /// This is used to honor the flag when piping output, similar to `cat -b`.
+    number_nonblank_from_cli: bool,
 }
 
 impl App {
@@ -81,12 +85,12 @@ impl App {
                 return true;
             }
             // Handle combined short flags
-            // Only count -n if it's the LAST flag in the combined form (so -p doesn't override it)
+            // Only count -n if its last occurrence comes after the last -p,
-            // or if -p is not present in the combined form
+            // or if -p is not present in the combined form.
             if arg_str.starts_with('-') && !arg_str.starts_with("--") && arg_str.len() > 2 {
                 let chars: Vec<char> = arg_str.chars().skip(1).collect();
-                let n_pos = chars.iter().position(|&c| c == 'n');
+                let n_pos = chars.iter().rposition(|&c| c == 'n');
-                let p_pos = chars.iter().position(|&c| c == 'p');
+                let p_pos = chars.iter().rposition(|&c| c == 'p');
                 // -n is in the combined flag and either:
                 // - -p is not present, OR
                 // - -n comes after -p (so -n takes effect)
@@ -99,6 +103,29 @@ impl App {
             false
         });
 
+        // Check if the -b / --number-nonblank option was passed on the command line
+        // (before merging with config file and environment variables).
+        // This is needed to honor the -b flag when piping output, similar to `cat -b`.
+        // The same combined-flag logic applies as for -n above.
+        let number_nonblank_from_cli = wild::args_os().any(|arg| {
+            let arg_str = arg.to_string_lossy();
+            if arg_str == "-b" || arg_str == "--number-nonblank" {
+                return true;
+            }
+            // Handle combined short flags by comparing the last -b and -p occurrences.
+            if arg_str.starts_with('-') && !arg_str.starts_with("--") && arg_str.len() > 2 {
+                let chars: Vec<char> = arg_str.chars().skip(1).collect();
+                let b_pos = chars.iter().rposition(|&c| c == 'b');
+                let p_pos = chars.iter().rposition(|&c| c == 'p');
+                if let Some(b) = b_pos {
+                    if p_pos.is_none() || b > p_pos.unwrap() {
+                        return true;
+                    }
+                }
+            }
+            false
+        });
+
         let matches = Self::matches(interactive_output)?;
 
         if matches.get_flag("help") {
@@ -139,6 +166,7 @@ impl App {
             matches,
             interactive_output,
             number_from_cli,
+            number_nonblank_from_cli,
         })
     }
 
@@ -454,7 +482,8 @@ impl App {
                     .map(|s| s.as_str())
                     == Some("always")
                 || self.matches.get_flag("force-colorization")
-                || self.number_from_cli),
+                || self.number_from_cli
+                || self.number_nonblank_from_cli),
             tab_width: self
                 .matches
                 .get_one::<String>("tabs")
@@ -495,6 +524,8 @@ impl App {
             ),
             quiet_empty: self.matches.get_flag("quiet-empty"),
             unbuffered: self.matches.get_flag("unbuffered"),
+            number_nonblank: self.matches.get_flag("number-nonblank")
+                || self.number_nonblank_from_cli,
             theme: theme(self.theme_options()).to_string(),
             visible_lines: match self.matches.try_contains_id("diff").unwrap_or_default()
                 && self.matches.get_flag("diff")
@@ -613,6 +644,13 @@ impl App {
             ])));
         }
 
+        // Only line numbers for non-blank lines if `--number-nonblank`.
+        if self.matches.get_flag("number-nonblank") || self.number_nonblank_from_cli {
+            return Some(StyleComponents(HashSet::from([
+                StyleComponent::LineNumbers,
+            ])));
+        }
+
         // Plain if `--plain` is specified at least once.
         if self.matches.get_count("plain") > 0 {
             let mut components = HashSet::from([StyleComponent::Plain]);

src/bin/bat/clap_app.rs

@@ -97,6 +97,7 @@ pub fn build_app(interactive_output: bool) -> Command {
             Arg::new("plain")
                 .overrides_with("plain")
                 .overrides_with("number")
+                .overrides_with("number-nonblank")
                 .short('p')
                 .long("plain")
                 .action(ArgAction::Count)
@@ -277,6 +278,23 @@ pub fn build_app(interactive_output: bool) -> Command {
                      '--style=numbers'",
                 ),
         )
+        .arg(
+            Arg::new("number-nonblank")
+                .long("number-nonblank")
+                .overrides_with("number-nonblank")
+                .short('b')
+                .action(ArgAction::SetTrue)
+                .help("Show line numbers for non-blank lines only (alias for '--style=numbers').")
+                .long_help(
+                    "Only show line numbers for non-blank lines, no other decorations. This is an \
+                     alias for '--style=numbers'. Non-blank lines are lines that contain any \
+                     character before the line ending, including spaces and tabs. When used \
+                     together with --number (-n), --number-nonblank (-b) takes precedence.\n\n\
+                     Example:\n  \
+                     printf 'alpha\\n\\nbeta\\n' | bat -b\n  \
+                     numbers 'alpha' and 'beta', but skips the empty line.",
+                ),
+        )
         .arg(
             Arg::new("color")
                 .long("color")

src/config.rs

@@ -119,6 +119,10 @@ pub struct Config<'a> {
 
     /// Whether or not to use unbuffered input reading for streaming use cases
     pub unbuffered: bool,
+
+    /// Only number non-blank lines (like `cat -b`). Has no effect if `style_components` doesn't
+    /// include `LineNumbers`.
+    pub number_nonblank: bool,
 }
 
 #[cfg(all(feature = "minimal-application", feature = "paging"))]

src/controller.rs

@@ -276,10 +276,21 @@ impl Controller<'_> {
             }
             if !reached_eof {
                 if reader.read_line(&mut current_line_buffer)? {
-                    // Fill the buffer
+                    // Fill the buffer. In number-nonblank mode, don't advance the
+                    // line counter for empty lines (content-free lines that contain
+                    // only the line terminator).
+                    if self.config.number_nonblank
+                        && current_line_buffer
+                            .iter()
+                            .all(|&b| b == b'\r' || b == b'\n')
+                    {
+                        buffered_lines
+                            .push_back((mem::take(&mut current_line_buffer), current_line_number));
+                    } else {
                         buffered_lines
                             .push_back((mem::take(&mut current_line_buffer), current_line_number));
                         current_line_number += 1;
+                    }
                 } else {
                     // No more data to read
                     reached_eof = true;

src/decorations.rs

@@ -45,6 +45,14 @@ impl Decoration for LineNumberDecoration {
         continuation: bool,
         _printer: &InteractivePrinter,
     ) -> DecorationText {
+        if line_number == 0 {
+            // Blank line in number-nonblank mode: show empty space instead of a number.
+            return DecorationText {
+                text: self.color.paint(" ".repeat(self.width())).to_string(),
+                width: self.width(),
+            };
+        }
+
         if continuation {
             if line_number >= self.cached_wrap_invalid_at {
                 let new_width = self.cached_wrap.width + 1;

src/printer.rs

@@ -738,10 +738,17 @@ impl Printer for InteractivePrinter<'_> {
 
         // Line decorations.
         if self.panel_width > 0 {
+            let display_line_number =
+                if self.config.number_nonblank && line.trim_end_matches(['\r', '\n']).is_empty() {
+                    0
+                } else {
+                    line_number
+                };
+
             let decorations = self
                 .decorations
                 .iter()
-                .map(|d| d.generate(line_number, false, self));
+                .map(|d| d.generate(display_line_number, false, self));
 
             for deco in decorations {
                 write!(handle, "{} ", deco.text)?;

tests/integration_tests.rs

@@ -213,6 +213,106 @@ fn numbers_honored_from_cli_when_preceeded_by_plain_in_loop_through_mode() {
         .stdout("   1 line 1\n   2 line 2\n   3 line 3\n   4 line 4\n   5 line 5\n   6 line 6\n   7 line 7\n   8 line 8\n   9 line 9\n  10 line 10\n");
 }
 
+#[test]
+fn repeated_combined_flags_use_last_number_or_plain_flag() {
+    bat()
+        .arg("multiline.txt")
+        .arg("-npn")
+        .arg("--decorations=auto")
+        .assert()
+        .success()
+        .stdout("   1 line 1\n   2 line 2\n   3 line 3\n   4 line 4\n   5 line 5\n   6 line 6\n   7 line 7\n   8 line 8\n   9 line 9\n  10 line 10\n");
+
+    bat()
+        .arg("multiline.txt")
+        .arg("-pnp")
+        .arg("--decorations=auto")
+        .assert()
+        .success()
+        .stdout(
+            "line 1\nline 2\nline 3\nline 4\nline 5\nline 6\nline 7\nline 8\nline 9\nline 10\n",
+        );
+
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-pbp")
+        .arg("--decorations=auto")
+        .assert()
+        .success()
+        .stdout("line 1\n\n\n\nline 5\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nline 20\nline 21\n\n\nline 24\n\nline 26\n\n\n\nline 30\n");
+
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-bpb")
+        .arg("--decorations=auto")
+        .assert()
+        .success()
+        .stdout("   1 line 1\n     \n     \n     \n   2 line 5\n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n   3 line 20\n   4 line 21\n     \n     \n   5 line 24\n     \n   6 line 26\n     \n     \n     \n   7 line 30\n");
+}
+
+#[test]
+fn number_nonblank_style() {
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-b")
+        .arg("--decorations=always")
+        .assert()
+        .success()
+        .stdout("   1 line 1\n     \n     \n     \n   2 line 5\n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n   3 line 20\n   4 line 21\n     \n     \n   5 line 24\n     \n   6 line 26\n     \n     \n     \n   7 line 30\n");
+}
+
+#[test]
+fn number_nonblank_from_cli_in_loop_through_mode() {
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-b")
+        .assert()
+        .success()
+        .stdout("   1 line 1\n     \n     \n     \n   2 line 5\n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n   3 line 20\n   4 line 21\n     \n     \n   5 line 24\n     \n   6 line 26\n     \n     \n     \n   7 line 30\n");
+}
+
+#[test]
+fn number_nonblank_takes_precedence_over_number() {
+    // -bn should behave like -b
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-bn")
+        .arg("--decorations=always")
+        .assert()
+        .success()
+        .stdout("   1 line 1\n     \n     \n     \n   2 line 5\n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n   3 line 20\n   4 line 21\n     \n     \n   5 line 24\n     \n   6 line 26\n     \n     \n     \n   7 line 30\n");
+
+    // -nb should also behave like -b
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-nb")
+        .arg("--decorations=always")
+        .assert()
+        .success()
+        .stdout("   1 line 1\n     \n     \n     \n   2 line 5\n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n     \n   3 line 20\n   4 line 21\n     \n     \n   5 line 24\n     \n   6 line 26\n     \n     \n     \n   7 line 30\n");
+}
+
+#[test]
+fn number_nonblank_ignored_when_followed_by_plain() {
+    bat()
+        .arg("empty_lines.txt")
+        .arg("-bp")
+        .arg("--decorations=auto")
+        .assert()
+        .success()
+        .stdout("line 1\n\n\n\nline 5\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nline 20\nline 21\n\n\nline 24\n\nline 26\n\n\n\nline 30\n");
+}
+
+#[test]
+fn piped_output_with_number_nonblank_flag() {
+    bat()
+        .arg("-b")
+        .write_stdin("hello\n\nworld\n")
+        .assert()
+        .success()
+        .stdout("   1 hello\n     \n   2 world\n");
+}
+
 #[test]
 fn line_range_2_3() {
     bat()
@@ -2579,6 +2679,145 @@ fn no_first_line_fallback_when_mapping_to_invalid_syntax() {
         .stderr(predicate::str::contains("unknown syntax: 'InvalidSyntax'"));
 }
 
+#[test]
+fn stdin_detects_bash_from_first_line() {
+    let content = "#!/bin/bash\necho hi\n";
+
+    let detected_output = bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .write_stdin(content)
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    let explicit_output = bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .arg("--language=bash")
+        .write_stdin(content)
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    assert_eq!(
+        from_utf8(&detected_output).expect("output is valid utf-8"),
+        from_utf8(&explicit_output).expect("output is valid utf-8")
+    );
+}
+
+#[test]
+fn stdin_detects_diff_from_first_line() {
+    let content = "diff --git a/x b/y\n--- a/x\n+++ b/y\n@@ -1 +1 @@\n-old\n+new\n";
+
+    let detected_output = bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .write_stdin(content)
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    let explicit_output = bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .arg("--language=diff")
+        .write_stdin(content)
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    assert_eq!(
+        from_utf8(&detected_output).expect("output is valid utf-8"),
+        from_utf8(&explicit_output).expect("output is valid utf-8")
+    );
+}
+
+#[test]
+fn empty_stdin_does_not_detect_syntax() {
+    bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .write_stdin("")
+        .assert()
+        .success()
+        .stdout("")
+        .stderr("");
+}
+
+#[test]
+fn binary_stdin_does_not_detect_syntax_from_invalid_utf8_first_line() {
+    let content = b"#!/bin/bash\xff\necho hi\n";
+
+    let detected_output = bat()
+        .arg("--binary=as-text")
+        .arg("--color=always")
+        .arg("--style=plain")
+        .write_stdin(content.as_slice())
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    let plain_text_output = bat()
+        .arg("--binary=as-text")
+        .arg("--color=always")
+        .arg("--style=plain")
+        .arg("--language=txt")
+        .write_stdin(content.as_slice())
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    assert_eq!(
+        from_utf8(&detected_output).expect("output is valid utf-8"),
+        from_utf8(&plain_text_output).expect("output is valid utf-8")
+    );
+}
+
+#[test]
+fn explicit_language_overrides_stdin_first_line_detection() {
+    let content = "diff --git a/x b/y\n--- a/x\n+++ b/y\n@@ -1 +1 @@\n-old\n+new\n";
+
+    let detected_output = bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .write_stdin(content)
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    let explicit_output = bat()
+        .arg("--color=always")
+        .arg("--style=plain")
+        .arg("--language=json")
+        .arg("-")
+        .write_stdin(content)
+        .assert()
+        .success()
+        .get_output()
+        .stdout
+        .clone();
+
+    assert_ne!(
+        from_utf8(&detected_output).expect("output is valid utf-8"),
+        from_utf8(&explicit_output).expect("output is valid utf-8")
+    );
+}
+
 #[test]
 fn fallback_syntax_is_used_when_no_syntax_is_detected() {
     let content = "# comment\nfoo=bar\n";