From 13263c9f81e72f04c99d0c54c0c190fe79077f70 Mon Sep 17 00:00:00 2001
From: Martin Geisler <martin@geisler.net>
Date: Sun, 30 Oct 2022 10:21:11 +0100
Subject: [PATCH] Limit inputs to prevent OSS-Fuzz timeouts

I downloaded the failing test cases from OSS-Fuzz and ran the fuzzers
on each of them: they all finished in ~35 seconds on my laptop. The
timeout on OSS-Fuzz is 25 seconds, which explains the timeouts.

Limiting the input length to 100k bytes should help here and still
allow us to test all reasonable inputs.
---
 fuzz/fuzz_targets/fill_fast_path.rs   |  4 ++++
 fuzz/fuzz_targets/fill_first_fit.rs   |  4 ++++
 fuzz/fuzz_targets/fill_optimal_fit.rs |  4 ++++
 fuzz/fuzz_targets/refill.rs           |  4 ++++
 fuzz/fuzz_targets/unfill.rs           |  4 ++++
 fuzz/fuzz_targets/wrap_fast_path.rs   | 10 ++++++----
 6 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/fuzz/fuzz_targets/fill_fast_path.rs b/fuzz/fuzz_targets/fill_fast_path.rs
index 31966120..cdffc22c 100644
--- a/fuzz/fuzz_targets/fill_fast_path.rs
+++ b/fuzz/fuzz_targets/fill_fast_path.rs
@@ -2,6 +2,10 @@
 use libfuzzer_sys::fuzz_target;
 
 fuzz_target!(|input: (String, usize)| {
+    if input.0.len() > 100_000 {
+        return; // Avoid timeouts in OSS-Fuzz.
+    }
+
     let options = textwrap::Options::new(input.1);
     let fast = textwrap::fill(&input.0, &options);
     let slow = textwrap::fuzzing::fill_slow_path(&input.0, options);
diff --git a/fuzz/fuzz_targets/fill_first_fit.rs b/fuzz/fuzz_targets/fill_first_fit.rs
index fe44367f..8fb58307 100644
--- a/fuzz/fuzz_targets/fill_first_fit.rs
+++ b/fuzz/fuzz_targets/fill_first_fit.rs
@@ -4,6 +4,10 @@ use textwrap::Options;
 use textwrap::WrapAlgorithm;
 
 fuzz_target!(|input: (String, usize)| {
+    if input.0.len() > 100_000 {
+        return; // Avoid timeouts in OSS-Fuzz.
+    }
+
     let options = Options::new(input.1).wrap_algorithm(WrapAlgorithm::FirstFit);
     let _ = textwrap::fill(&input.0, &options);
 });
diff --git a/fuzz/fuzz_targets/fill_optimal_fit.rs b/fuzz/fuzz_targets/fill_optimal_fit.rs
index 4465eac2..b0452152 100644
--- a/fuzz/fuzz_targets/fill_optimal_fit.rs
+++ b/fuzz/fuzz_targets/fill_optimal_fit.rs
@@ -4,6 +4,10 @@ use textwrap::Options;
 use textwrap::WrapAlgorithm;
 
 fuzz_target!(|input: (String, usize)| {
+    if input.0.len() > 100_000 {
+        return; // Avoid timeouts in OSS-Fuzz.
+    }
+
     let options = Options::new(input.1).wrap_algorithm(WrapAlgorithm::new_optimal_fit());
     let _ = textwrap::fill(&input.0, &options);
 });
diff --git a/fuzz/fuzz_targets/refill.rs b/fuzz/fuzz_targets/refill.rs
index 16073d0d..a45e6159 100644
--- a/fuzz/fuzz_targets/refill.rs
+++ b/fuzz/fuzz_targets/refill.rs
@@ -2,5 +2,9 @@
 use libfuzzer_sys::fuzz_target;
 
 fuzz_target!(|input: (String, usize)| {
+    if input.0.len() > 100_000 {
+        return; // Avoid timeouts in OSS-Fuzz.
+    }
+
     let _ = textwrap::refill(&input.0, input.1);
 });
diff --git a/fuzz/fuzz_targets/unfill.rs b/fuzz/fuzz_targets/unfill.rs
index f9a1bfb3..ad0b49b7 100644
--- a/fuzz/fuzz_targets/unfill.rs
+++ b/fuzz/fuzz_targets/unfill.rs
@@ -2,5 +2,9 @@
 use libfuzzer_sys::fuzz_target;
 
 fuzz_target!(|input: String| {
+    if input.len() > 100_000 {
+        return; // Avoid timeouts in OSS-Fuzz.
+    }
+
     let _ = textwrap::unfill(&input);
 });
diff --git a/fuzz/fuzz_targets/wrap_fast_path.rs b/fuzz/fuzz_targets/wrap_fast_path.rs
index 8a2ca84e..acc65b53 100644
--- a/fuzz/fuzz_targets/wrap_fast_path.rs
+++ b/fuzz/fuzz_targets/wrap_fast_path.rs
@@ -2,15 +2,17 @@
 use libfuzzer_sys::fuzz_target;
 
 fuzz_target!(|input: (String, usize)| {
-    // Filter out multi-line input.
+    if input.0.len() > 100_000 {
+        return; // Avoid timeouts in OSS-Fuzz.
+    }
+
     if input.0.contains('\n') {
-        return;
+        return; // Filter out multi-line input.
     }
 
+    let options = textwrap::Options::new(input.1);
     let mut fast = Vec::new();
     let mut slow = Vec::new();
-
-    let options = textwrap::Options::new(input.1);
     textwrap::fuzzing::wrap_single_line(&input.0, &options, &mut fast);
     textwrap::fuzzing::wrap_single_line_slow_path(&input.0, &options, &mut slow);
     assert_eq!(fast, slow);