dirname: add fuzzer to test GNU compatibility

Author: sylvestre

.github/workflows/fuzzing.yml

@@ -96,6 +96,7 @@ jobs:
           - { name: fuzz_parse_time, should_pass: true }
           - { name: fuzz_seq_parse_number, should_pass: true }
           - { name: fuzz_non_utf8_paths, should_pass: true }
+          - { name: fuzz_dirname, should_pass: true }
 
     steps:
     - uses: actions/checkout@v6

fuzz/Cargo.lock

@@ -41,6 +41,7 @@ uu_split = { path = "../src/uu/split" }
 uu_tr = { path = "../src/uu/tr" }
 uu_env = { path = "../src/uu/env" }
 uu_cksum = { path = "../src/uu/cksum" }
+uu_dirname = { path = "../src/uu/dirname" }
 
 [[bin]]
 name = "fuzz_date"
@@ -149,3 +150,9 @@ name = "fuzz_non_utf8_paths"
 path = "fuzz_targets/fuzz_non_utf8_paths.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "fuzz_dirname"
+path = "fuzz_targets/fuzz_dirname.rs"
+test = false
+doc = false

fuzz/Cargo.toml

@@ -0,0 +1,211 @@
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+use uu_dirname::uumain;
+
+use rand::Rng;
+use rand::prelude::IndexedRandom;
+use std::ffi::OsString;
+
+use uufuzz::CommandResult;
+use uufuzz::{compare_result, generate_and_run_uumain, generate_random_string, run_gnu_cmd};
+
+static CMD_PATH: &str = "dirname";
+
+fn generate_dirname_args() -> Vec<String> {
+    let mut rng = rand::rng();
+    let mut args = Vec::new();
+
+    // 20% chance to include -z/--zero flag
+    if rng.random_bool(0.2) {
+        if rng.random_bool(0.5) {
+            args.push("-z".to_string());
+        } else {
+            args.push("--zero".to_string());
+        }
+    }
+
+    // 30% chance to use one of the specific issue #8924 cases
+    if rng.random_bool(0.3) {
+        let issue_cases = [
+            "foo//.",
+            "foo/./",
+            "foo/bar/./",
+            "bar//.",
+            "test/./",
+            "a/b/./",
+            "x//.",
+            "dir/subdir/./",
+        ];
+        args.push(issue_cases.choose(&mut rng).unwrap().to_string());
+    } else {
+        // Generate 1-3 path arguments normally
+        let num_paths = rng.random_range(1..=3);
+        for _ in 0..num_paths {
+            args.push(generate_path());
+        }
+    }
+
+    args
+}
+
+fn generate_path() -> String {
+    let mut rng = rand::rng();
+
+    // Different types of paths to test
+    let path_type = rng.random_range(0..15);
+
+    match path_type {
+        // Simple paths
+        0 => generate_random_string(rng.random_range(1..=20)),
+
+        // Paths with slashes
+        1 => {
+            let mut path = String::new();
+            let components = rng.random_range(1..=5);
+            for i in 0..components {
+                if i > 0 {
+                    path.push('/');
+                }
+                path.push_str(&generate_random_string(rng.random_range(1..=10)));
+            }
+            path
+        }
+
+        // Root path
+        2 => "/".to_string(),
+
+        // Absolute paths
+        3 => {
+            let mut path = "/".to_string();
+            let components = rng.random_range(1..=4);
+            for _ in 0..components {
+                path.push_str(&generate_random_string(rng.random_range(1..=8)));
+                path.push('/');
+            }
+            // Remove trailing slash sometimes
+            if rng.random_bool(0.5) && path.len() > 1 {
+                path.pop();
+            }
+            path
+        }
+
+        // Paths ending with "/." (specific case from issue #8924)
+        4 => {
+            let base = if rng.random_bool(0.3) {
+                "/".to_string()
+            } else {
+                format!("/{}", generate_random_string(rng.random_range(1..=10)))
+            };
+            format!("{}.", base)
+        }
+
+        // Paths with multiple slashes
+        5 => {
+            let base = generate_random_string(rng.random_range(1..=10));
+            format!(
+                "///{}//{}",
+                base,
+                generate_random_string(rng.random_range(1..=8))
+            )
+        }
+
+        // Paths with dots
+        6 => {
+            let components = [".", "..", "...", "...."];
+            let chosen = components.choose(&mut rng).unwrap();
+            if rng.random_bool(0.5) {
+                format!("/{}", chosen)
+            } else {
+                chosen.to_string()
+            }
+        }
+
+        // Single character paths
+        7 => {
+            let chars = ['a', 'x', '1', '-', '_', '.'];
+            chars.choose(&mut rng).unwrap().to_string()
+        }
+
+        // Empty string (edge case)
+        8 => "".to_string(),
+
+        // Issue #8924 specific cases: paths like "foo//."
+        9 => {
+            let base = generate_random_string(rng.random_range(1..=10));
+            format!("{}//.", base)
+        }
+
+        // Issue #8924 specific cases: paths like "foo/./"
+        10 => {
+            let base = generate_random_string(rng.random_range(1..=10));
+            format!("{}/./", base)
+        }
+
+        // Issue #8924 specific cases: paths like "foo/bar/./"
+        11 => {
+            let base1 = generate_random_string(rng.random_range(1..=8));
+            let base2 = generate_random_string(rng.random_range(1..=8));
+            format!("{}/{}/./", base1, base2)
+        }
+
+        // More complex patterns with ./ and multiple slashes
+        12 => {
+            let base = generate_random_string(rng.random_range(1..=10));
+            let patterns = ["/./", "//./", "//.//", "/.//"];
+            let pattern = patterns.choose(&mut rng).unwrap();
+            format!("{}{}", base, pattern)
+        }
+
+        // Patterns with .. and multiple slashes
+        13 => {
+            let base = generate_random_string(rng.random_range(1..=10));
+            let patterns = ["/..", "//..", "/../", "//..//"];
+            let pattern = patterns.choose(&mut rng).unwrap();
+            format!("{}{}", base, pattern)
+        }
+
+        // Complex paths with special cases
+        _ => {
+            let special_endings = [".", "..", "/.", "/..", "//", "/", "/./.", "//.", "./"];
+            let base = generate_random_string(rng.random_range(1..=15));
+            let ending = special_endings.choose(&mut rng).unwrap();
+            format!("{}{}", base, ending)
+        }
+    }
+}
+
+fuzz_target!(|_data: &[u8]| {
+    let dirname_args = generate_dirname_args();
+    let mut args = vec![OsString::from("dirname")];
+    args.extend(dirname_args.iter().map(OsString::from));
+
+    let rust_result = generate_and_run_uumain(&args, uumain, None);
+
+    let gnu_result = match run_gnu_cmd(CMD_PATH, &args[1..], false, None) {
+        Ok(result) => result,
+        Err(error_result) => {
+            eprintln!("Failed to run GNU command:");
+            eprintln!("Stderr: {}", error_result.stderr);
+            eprintln!("Exit Code: {}", error_result.exit_code);
+            CommandResult {
+                stdout: String::new(),
+                stderr: error_result.stderr,
+                exit_code: error_result.exit_code,
+            }
+        }
+    };
+
+    compare_result(
+        "dirname",
+        &format!("{:?}", &args[1..]),
+        None,
+        &rust_result,
+        &gnu_result,
+        false,
+    );
+});