style: make clang-format break long lines #21223

Without limit clang-format would join manually broken lines into a single very long line, hindering readability.

@vasild do you have an example of this? The only instances I've seen are argument/parameter lists, which should be fixed by #21221.

Yes (those are not affected by BinPackParameters and BinPackArguments from #21221):

before (without limit, master):

    txNew.vin[0].scriptSig = CScript() << 486604799 << CScriptNum(4) << std::vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));

//

                    for (std::set<uint256>::iterator it = pto->m_tx_relay->setInventoryTxToSend.begin(); it != pto->m_tx_relay->setInventoryTxToSend.end(); it++) {

//

        if (m_shift < n || m_shift >= std::numeric_limits<uint64_t>::max() || m_shift < std::numeric_limits<I>::min() || m_shift > std::numeric_limits<I>::max()) throw std::ios_base::failure("differential value overflow");

//

    std::vector<CBlockIndex*>::const_iterator lower = std::lower_bound(vChain.begin(), vChain.end(), blockparams,
        [](CBlockIndex* pBlock, const std::pair<int64_t, int>& blockparams) -> bool { return pBlock->GetBlockTimeMax() < blockparams.first || pBlock->nHeight < blockparams.second; });

after (with limit, this PR):

    txNew.vin[0].scriptSig = CScript()
                             << 486604799 << CScriptNum(4)
                             << std::vector<unsigned char>(
                                    (const unsigned char*)pszTimestamp,
                                    (const unsigned char*)pszTimestamp + strlen(pszTimestamp));

//

                    for (std::set<uint256>::iterator it =
                             pto->m_tx_relay->setInventoryTxToSend.begin();
                         it != pto->m_tx_relay->setInventoryTxToSend.end(); it++) {

//

        if (m_shift < n || m_shift >= std::numeric_limits<uint64_t>::max() ||
            m_shift < std::numeric_limits<I>::min() || m_shift > std::numeric_limits<I>::max())
            throw std::ios_base::failure("differential value overflow");

//

    std::vector<CBlockIndex*>::const_iterator lower = std::lower_bound(
        vChain.begin(), vChain.end(), blockparams,
        [](CBlockIndex* pBlock, const std::pair<int64_t, int>& blockparams) -> bool {
            return pBlock->GetBlockTimeMax() < blockparams.first ||
                   pBlock->nHeight < blockparams.second;
        });

Maybe I did not pick the best examples, see the output of git grep '.{100,}' '*.cpp' '*.h' (or 150 for the extreme cases).

@jnewbery, I just realized that you asked for an example where clang-format would join a manually broken line and I gave examples where it would break a long line (the opposite).

Indeed I cannot find such examples, other than functions' arguments/parameters, which is addressed in #21221.

Closing this in favor of #21221. Will reopen if I find examples where manually broken lines get joined (with #21221 merged).

Thanks @vasild!