ecdsa: Fix uninitialized field element in signature verification #1838

1. 
   mllwchrry commented at 5:34 pm on March 20, 2026: none

   Fixes an uninitialized variable issue in src/ecdsa_impl.h where the xr field element may not be fully initialized before use.

   This error was exposed while I was testing the improved test coverage in CI. The initial plan was to simplify the configuration of modules in CI by enabling all modules by default and testing the disabling of each module independently.

   Error: src/field_impl.h:157:20: error: ‘xr.normalized’ may be used uninitialized [-Werror=maybe-uninitialized].

   The error occurred when running the x86_64: Linux (Debian stable) (-DDETERMINISTIC, gcc-snapshot) CI job, which uses GCC 16 (snapshot) with strict compilation flags. See this action run for reference: https://github.com/mllwchrry/secp256k1/actions/runs/23301905657/job/67769464777.

2. ecdsa: Fix uninitialized variable in secp256k1_ecdsa_sig_verify 74db386985
3. real-or-random added the label tweak/refactor on Mar 23, 2026
4. 
   mllwchrry commented at 2:52 pm on March 24, 2026: none

   Closing in favor of #1839.
5. mllwchrry closed this on Mar 24, 2026

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Contributors
mllwchrry

Labels
tweak/refactor