From f30fbe70d42c0d19593e89796628a0781be49378 Mon Sep 17 00:00:00 2001
From: Andrew Poelstra <apoelstra@wpsoftware.net>
Date: Fri, 12 Mar 2021 20:53:33 +0000
Subject: [PATCH] remove panic from C invalid-argument callbacks

---
 secp256k1-sys/src/lib.rs | 10 ++++++----
 src/lib.rs               |  2 +-
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/secp256k1-sys/src/lib.rs b/secp256k1-sys/src/lib.rs
index d8ec28182..9474b25bb 100644
--- a/secp256k1-sys/src/lib.rs
+++ b/secp256k1-sys/src/lib.rs
@@ -580,7 +580,7 @@ pub unsafe fn secp256k1_context_destroy(ctx: *mut Context) {
 ///
 /// A callback function to be called when an illegal argument is passed to
 /// an API call. It will only trigger for violations that are mentioned
-/// explicitly in the header. **This will cause a panic**.
+/// explicitly in the header.
 ///
 /// The philosophy is that these shouldn't be dealt with through a
 /// specific return value, as calling code should not have branches to deal with
@@ -600,13 +600,14 @@ pub unsafe extern "C" fn rustsecp256k1_v0_4_0_default_illegal_callback_fn(messag
     use core::str;
     let msg_slice = slice::from_raw_parts(message as *const u8, strlen(message));
     let msg = str::from_utf8_unchecked(msg_slice);
-    panic!("[libsecp256k1] illegal argument. {}", msg);
+    #[cfg(feature = "std")]
+    println!("[libsecp256k1] illegal argument. {}", msg);
 }
 
 /// **This function is an override for the C function, this is the an edited version of the original description:**
 ///
 /// A callback function to be called when an internal consistency check
-/// fails. **This will cause a panic**.
+/// fails.
 ///
 /// This can only trigger in case of a hardware failure, miscompilation,
 /// memory corruption, serious bug in the library, or other error would can
@@ -623,7 +624,8 @@ pub unsafe extern "C" fn rustsecp256k1_v0_4_0_default_error_callback_fn(message:
     use core::str;
     let msg_slice = slice::from_raw_parts(message as *const u8, strlen(message));
     let msg = str::from_utf8_unchecked(msg_slice);
-    panic!("[libsecp256k1] internal consistency check failed {}", msg);
+    #[cfg(feature = "std")]
+    println!("[libsecp256k1] internal consistency check failed {}", msg);
 }
 
 #[cfg(not(rust_secp_no_symbol_renaming))]
diff --git a/src/lib.rs b/src/lib.rs
index 7b66a7258..d893a4fd6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -938,7 +938,7 @@ mod tests {
 
     #[cfg(not(target_arch = "wasm32"))]
     #[test]
-    #[should_panic]
+    #[should_panic(expected = "assertion failed")]
     fn test_panic_raw_ctx() {
         let ctx_vrfy = Secp256k1::verification_only();
         let raw_ctx_verify_as_full = unsafe {Secp256k1::from_raw_all(ctx_vrfy.ctx)};