* fix: replace seemingly buggy loop with std::adjacent_find
* Remove redundant variable declaration
* use std::fill instead of a loop
* remove a few raw for loops
2e68ffaf205866e4cea71f64e79bbfb89e17280a [doc] descriptor: explain GetPubKey() usage with cached public key (Sjors Provoost)
2290269759ad10cc2e35958c7b0a63f3a7608621 scripted-diff: rename DescriptorImpl m_script_arg to m_subdescriptor_arg (Sjors Provoost)
Pull request description:
I found the name `m_script_arg` to be confusing while reviewing https://github.com/bitcoin/bitcoin/pull/14646#discussion_r240677238. @sipa let me know if `m_subdescriptor_arg` is completely wrong.
I also added an explanation of why we call `GetPubKey` when we don't ask it for a public key.
ACKs for top commit:
laanwj:
ACK 2e68ffaf205866e4cea71f64e79bbfb89e17280a
Tree-SHA512: 06698e9a91cdda93c043a82732793f0ad3cd91daa2513565953e9fa048d5573322fb534e9d0ea9ab736e6366be5921e2b8699c4f4b3693edab48039aaae06f78
6285a318d77dbfdf50f893963ebfb2973746f757 Remove redundant WalletController::addWallet slot (Hennadii Stepanov)
Pull request description:
~~Fix #15453.~~ It is fixed by https://github.com/bitcoin/bitcoin/pull/16348#issuecomment-509308347
The _only_ reason of these lines on master (8c69fae94410f54bad13be0f34d54370fddbf4b3)
2679bb8919/src/qt/walletcontroller.cpp (L121-L128)
is to `Q_EMIT walletAdded(wallet_model);` in a thread-safe manner;
This PR makes this in a line of code:
1b83875006/src/qt/walletcontroller.cpp (L121)
EDITED:
To establish the ownership of a new `WalletModel` object is not necessary on the master (https://github.com/bitcoin/bitcoin/pull/16349#discussion_r301679192 by **promag**).
But:
> it's good habit to set ownership
And I agree. It is a safe practice.
ACKs for top commit:
promag:
ACK 6285a318d77dbfdf50f893963ebfb2973746f757.
jonasschnelli:
utACK 6285a318d77dbfdf50f893963ebfb2973746f757
ryanofsky:
utACK 6285a318d77dbfdf50f893963ebfb2973746f757. Only change since last review is rebasing and restoring a deleted comment. I do think the comments I suggested last review would be better than this one, but this is at least better than before.
Tree-SHA512: 90370cb1fe853b84dd16c3781ba4f97f3f4deca56bba0203e457f37b3220fd13228cf8495fd882ff18b7c782c27544cc2e7a88aaec5b69b9ef6d8626bdaaf332
b2ea20d3302275a62bbdfdb96169c6788fe7b9c1 doc: Fix grammar and punctuation in developer notes (Kristian Kramer)
Pull request description:
This pull request is regarding minor grammar and punctuation errors in the developer notes. There were no modifications to the existing code, only alterations to fix the grammar and punctuation in the text to make the developer notes more understandable and easier to read.
ACKs for top commit:
fanquake:
ACK b2ea20d3302275a62bbdfdb96169c6788fe7b9c1
Tree-SHA512: eef990b7e7645b44a1ab0b057f4df35894c307fd23cc861a10d3cc80e7fe7fe8f5b94467f8224cc8a7aaa226f82be3a1f0460a45f3e25e5dab1e1d333c9edbc0
fa8489a15511f61a372473927e73c34692bbec23 test: Add test for BIP30 duplicate tx (MarcoFalke)
77770d95e2838d7665fa8f621e9e83d79f9b3196 test: Properly serialize BIP34 coinbase height (MarcoFalke)
Pull request description:
This adds a test for BIP30 to check that duplicate txs can exist in the blockchain given the first one was completely spent when the second one is added. (Requested by ajtowns in https://github.com/bitcoin/bitcoin/pull/16333#issuecomment-508604071)
We can not add a test that a later duplicate tx overwrites a previous one, because BIP30 is always enforced on regtest. If someone feels strongly about such a test, some Bitcoin Core code would have to be modified, which can be done in a follow up pull request.
Also, add a commit to fix the BIP34 test failures reported in https://github.com/bitcoin/bitcoin/pull/14633#issue-227712540
ACKs for top commit:
laanwj:
Code review ACK fa8489a15511f61a372473927e73c34692bbec23
Tree-SHA512: c707d0bdc93937263876b603425b53322a2a9f9ec3f50716ae2fa9de8ddc644beb22b26c1bfde7f4aab102633e096b354ef380db919176bd2cb44a2828f884aa
05fdb97df46d0a0675b93e9791bd5d498e5e5117 [doc] Update and extend benchmarking.md (Antoine Riard)
Pull request description:
Trying to make benchmarking docs a bit more friendly.
If you have any more ideas, specially on the Notes section, which component need more benchmarks.
(oh isn't a write-up somewhere to generate flame graphs for core ?)
ACKs for top commit:
jonatack:
ACK 05fdb97df46d0a0675b93e9791bd5d498e5e5117
fanquake:
ACK 05fdb97df46d0a0675b93e9791bd5d498e5e5117 - with the single nit.
Tree-SHA512: 1d31438065cab12b43b0227c1c774b412ac3d9d46d4cbe69cfe753424a81e51839777e815c70880da8ae6c8fb95221dc7559334eeb550221e8a76fb20a370f75
d6b3640ac732f6f66a8cb6761084d1beecc8a876 [test] walletcreatefundedpsbt: check RBF is disabled when -walletrbf=0 (Sjors Provoost)
9ed062b5685eb6227d694572cb0f7bfbcc151b36 [doc] rpc: remove "fallback to" from RBF default help (Sjors Provoost)
4fcb698bc2bb74171cd3a14b94f9882d8e19e9fb [rpc] walletcreatefundedpsbt: use wallet default RBF (Sjors Provoost)
Pull request description:
The `walletcreatefundedpsbt` RPC call currently ignores `-walletrbf` and defaults to not use RBF. This PR fixes that.
This PR also replaces UniValue in `ConstructTransaction` with a `bool` in preparation of moving this helper method out of the RPC codebase entirely. This may be a bit overkill, but does slightly simplify it.
Fixes#15878
ACKs for top commit:
achow101:
Code Review ACK d6b3640ac732f6f66a8cb6761084d1beecc8a876
l2a5b1:
re-ACK d6b3640
MarcoFalke:
ACK d6b3640ac732f6f66a8cb6761084d1beecc8a876
Tree-SHA512: 55b9bccd1ef36b54f6b34793017dc0721103099ad3761b3b04862291ee13d6915915d4dbb1a8567924fa56e5e95dfe10eec070e06701610e70c87f8ea92b2a00
b078067b9c2aa1d259395198005fab470ea4e39d gui: Remove unused RPCConsole::tabFocus (João Barbosa)
Pull request description:
Added in #14573 but not used, so begone.
ACKs for top commit:
practicalswift:
utACK b078067b9c2aa1d259395198005fab470ea4e39d
hebasto:
ACK b078067b9c2aa1d259395198005fab470ea4e39d
laanwj:
ACK b078067b9c2aa1d259395198005fab470ea4e39d, there's nothing really to test here
Tree-SHA512: 237276dea4d174b5fca34855447146f79c3faaae7179f4245c70e2070b49282d95f886b1be6d2a33713c81a254f4483a4e4bf850053a8dcb18a3a897bd3da08e
4d4e4c6448 Suggested interfaces::Chain cleanups from #15288 (Russell Yanofsky)
Pull request description:
Mostly documentation improvements requested in the last review of #15288 before it was merged (https://github.com/bitcoin/bitcoin/pull/15288#pullrequestreview-210241864)
Tree-SHA512: 64e912520bbec20a44032f265a8cf3f11ad7f5126c8626b5ad5e888227b1f92ecb321522fab4bbbd613230b55450abd6ace023631d0a4f357a780d65c5638bfe
ae311bc036e9461187f5396751d2e63a71248715 Fix autostart filenames on Linux (Hennadii Stepanov)
Pull request description:
Currently, on master the `bitcoin-test.lnk` and `bitcoin-regtest.lnk` files do not work as autostart application `.desktop` files.
This PR fixes it.
Refs:
- #7045
- [Autostart Of Applications During Startup](https://standards.freedesktop.org/autostart-spec/autostart-spec-latest.html)
ACKs for top commit:
promag:
utACK ae311bc, weird why extension `.lnk` was used in #7045.
laanwj:
Code review ACK ae311bc036e9461187f5396751d2e63a71248715
Tree-SHA512: 210cc346600d52b0a262c81ed5f258365a3cea2e5522f4b5f4798fd3b54f45ed82aba68eefae59a6b6f1d8e4d00221476c23bdffc038f16f2f45c1acc837f522
fa0d0ff6e1bee60fde63724ae28a51aac5a94d4a Remove unused bits from the service flags enum (MarcoFalke)
Pull request description:
Remove all bits that have no BIP specification nor can be observed on the active network
ACKs for top commit:
practicalswift:
utACK fa0d0ff6e1bee60fde63724ae28a51aac5a94d4a
LarryRuane:
utACK fa0d0ff6e1bee60fde63724ae28a51aac5a94d4a
promag:
ACK fa0d0ff6e1bee60fde63724ae28a51aac5a94d4a.
laanwj:
ACK fa0d0ff6e1bee60fde63724ae28a51aac5a94d4a
Tree-SHA512: 6342017bfd4c2a39c998fbb02497931b11892e1cb60fc13b948b91812f281b605a25a3fdc0d5358dff18da4e82eb4eb4de95c43c7e76ecb331c1c3985443dd21
96b6dd468a4cb6077d1a2267d620d99d39aac7d0 Remove redundant pre-TopUpKeypool checks (Gregory Sanders)
Pull request description:
TopUpKeypool already has a quick check for `IsLocked()`
ACKs for top commit:
achow101:
ACK 96b6dd468a4cb6077d1a2267d620d99d39aac7d0 Reviewed the diff and checked that the `if (!IsLocked()) TopUpKeypool()` pattern is changed everywhere.
Tree-SHA512: 36f5ae1be611404656ac855763e569fd3b5e932db8170f39ebda74300aa02062774b2c28ce6cf00f2ccc0e3550de58df36efa9097e24f0a51f2809b8a489c95a
0512f0521a63a4cd65e5e93ac1c44e4d54604605 depends: expat 2.2.7 (fanquake)
Pull request description:
Major changes in expat 2.2.7:
* [#186](https://github.com/libexpat/libexpat/issues/186) [#262](https://github.com/libexpat/libexpat/pull/262) Fix extraction of namespace prefixes from XML names;
XML names with multiple colons could end up in the
wrong namespace, and take a high amount of RAM and CPU
resources while processing, opening the door to use for denial-of-service attacks
* [#227](https://github.com/libexpat/libexpat/pull/227) Autotools: Add --without-examples and --without-tests
Full changelog is available [here](https://github.com/libexpat/libexpat/blob/R_2_2_7/expat/Changes#L5).
ACKs for top commit:
laanwj:
ACK 0512f0521a63a4cd65e5e93ac1c44e4d54604605
Tree-SHA512: 45162a9b0011107fd59a97dae7b5eb61989dafbec26b1ee497d1b11bf5c6a119971096899caa2998648b82a62db57c629a1560453557146c2496b39a7f3f8de9
84edfc72e5eba3dde824ebd0626e97929a0b1bca Update doc and CI config (qmma)
48bcb2ac249e0e666ce638bb29124558b3283c16 Disable other targets when enable-fuzz is set (qmma)
Pull request description:
This is to fix https://github.com/bitcoin/bitcoin/issues/16094
When the `enable-fuzz` flag is set, disable all other binary targets.
ACKs for top commit:
MarcoFalke:
ACK 84edfc72e5eba3dde824ebd0626e97929a0b1bca (only checked that travis compiled this)
Tree-SHA512: f4ac80526388a67709986b22de88b00bf93ab44ae31a20bd4d8923a4982ab97e015a9f13010081d6ecf6c23ae8afeac7ca9d849d198ce6ebe239aa3127151efc
* use unique_ptr instead of shared
Signed-off-by: pasta <pasta@dashboost.org>
* unique_ptr over shared_ptr
Signed-off-by: pasta <pasta@dashboost.org>
* remove unneeded ptr
Signed-off-by: pasta <pasta@dashboost.org>
* Adjust IsTxSafeForMining checks
Signed-off-by: pasta <pasta@dashboost.org>
* use const ref
Signed-off-by: pasta <pasta@dashboost.org>
* add a todo
Signed-off-by: pasta <pasta@dashboost.org>
* use optional instead of magic max value
fixes a hypothetical bug where myIdx is not "initialized" (ie max), and we sleep forever
Signed-off-by: pasta <pasta@dashboost.org>
* simplify relay check
Signed-off-by: pasta <pasta@dashboost.org>
* use count_if instead of a loop
Signed-off-by: pasta <pasta@dashboost.org>
* add a few vector reserves
Signed-off-by: pasta <pasta@dashboost.org>
a2a6c8f4535c0c3c5f05714d64b238fc5a839233 rpc: remove duplicate solvable field from getaddressinfo (fanquake)
Pull request description:
Also added optional to `iscompressed`.
Tree-SHA512: 28442a9dbfb2a9992b9b57142fa13d374d39444f04ae63460cb6330d896160cfd4b9651a3e231893eac3142ce55eff597a54cbafd3b57ffa46d3711c64044acb
Co-authored-by: Wladimir J. van der Laan <laanwj@gmail.com>
fae91a09c453a9a95c382df765bd71e54698d5b2 test: Remove incorrect and unused try-block in assert_debug_log (MarcoFalke)
Pull request description:
This try block has accidentally been added by me in fa3e9f7627784ee00980590e5bf044a0e1249999.
It was unused all the time, but commit 6011c9d72d1df5c2cd09de6f85c21eb4f7eb1ba8 added a `return` in the finally block, muting all exceptions.
This can be tested by adding an `assert False` after any `with ...assert_debug_log...:` line.
ACKs for top commit:
laanwj:
ACK fae91a09c453a9a95c382df765bd71e54698d5b2
ryanofsky:
utACK fae91a09c453a9a95c382df765bd71e54698d5b2. I didn't know returning inside a `finally` block would cancel pending exceptions or return values, but I guess this makes sense and is a good thing to be aware of.
Tree-SHA512: 47ed0165062060e9af055a3e92f1a529cd41d00476bfad64e3cd141ae084d22f926a343bb1257717e164e15459a59ab66aed198c95d18bf780d8cb0b76aa3298
6011c9d72d1df5c2cd09de6f85c21eb4f7eb1ba8 QA: fix rpc_setban.py race (Jonas Schnelli)
Pull request description:
The new `rpc_setban.py` test failes regularly on CIs due to a race between injecting the ban and testing the log "on the other side".
The problem is, that the test immediately after the `addnode` command on node0 checks for the `dropped (banned)` entry on node1 (without giving some time).
Adding a 2 seconds sleep seems to solve the race (I guess there is no better event-driven delay).
Example of a failed test: https://bitcoinbuilds.org/index.php?ansilog=bf743910-103f-4b54-9a97-960c471061bd.log#l2906
Top commit has no ACKs.
Tree-SHA512: 680f8ea3e5ddb07e93f824f1aeff4a459e25e6c14715a39fc7670e50506d7cf25925348672c5c2d8ba3e1243ccf5effbc2456bcd094fb96868349f8d26e008f1
fadd6e0d2a6a5104aa215f456987ad7374bcc6ce doc: Remove mention of renamed mapBlocksUnlinked (MarcoFalke)
Pull request description:
This has been renamed to `m_blocks_unlinked`. Instead of adjusting the internal variable name in the help text, explain the debug flag with more general terms.
ACKs for top commit:
practicalswift:
ACK fadd6e0d2a6a5104aa215f456987ad7374bcc6ce -- diff looks correct
promag:
ACK fadd6e0d2a6a5104aa215f456987ad7374bcc6ce.
laanwj:
ACK fadd6e0d2a6a5104aa215f456987ad7374bcc6ce (as argument help is not translated this doesn't have to wait for the split-off)
Tree-SHA512: 8ad64965ab5bbba4b92933a5adcb0c9eda5bdb0cc080840a4a97b12c67f41f9b789fd289df4932d748f5a7eebc7305a000f03ceb968a78c9b5d9f34af61f0b15
dbdc758c27cfdda9d255742b6c6ff4d1b7be82df doc: Improve doxygen readme navigation section (Jon Layton)
c15ac2c0aa45c59aee6d36c2d6d5210290dc601c doc: Move doxygen intro to file for USE_MDFILE_AS_MANPAGE (Jon Layton)
Pull request description:
With `USE_MDFILE_AS_MAINPAGE`, this moves the introductory Doxygen comment to its own file. This makes `bitcoind.cpp` cleaner.
It also removes the `\mainpage` header text, which was smaller than the section titles, and improves the Navigation section.
ACKs for top commit:
promag:
ACK dbdc758c27cfdda9d255742b6c6ff4d1b7be82df.
Tree-SHA512: 9352baad655877437913b74dc8888a71d1cccf55a837657ee2630fde3f427d0f0339155b7ab3d9e63a9edb9d53512d747eafcb11987a7c26c47a6df2eca93351
c4606b84329d760d7cee144bebe05807857edaae Add Travis check for single parameter constructors not marked "explicit" (practicalswift)
Pull request description:
Make single parameter constructors `explicit` (C++11).
Rationale from the developer notes:
> - By default, declare single-argument constructors `explicit`.
> - *Rationale*: This is a precaution to avoid unintended conversions that might
> arise when single-argument constructors are used as implicit conversion
> functions.
ACKs for top commit:
laanwj:
ACK c4606b84329d760d7cee144bebe05807857edaae
Tree-SHA512: 3e6fd51935fd93b2604b2188664692973d0897469f814cd745b5147d71b99ea5d73c1081cfde9f6393f51f56969e412fcda35d2d54e938a3235b8d40945f31fd
9f9db39041 QA/mininode: Send all headers upfront in send_blocks_and_test to avoid sending an unconnected one (Luke Dashjr)
Pull request description:
While this doesn't currently trigger any problems, the network protocol does expect headers to be sent connectable in normal circumstances, and if too many are sent out of order will disconnect the peer.
ACKs for commit 9f9db3:
Tree-SHA512: 25b88718e4ba3d31aed2de7ece23fab9a0737fd6536c5e618ea8eb5a3a217dab0dffaebc4892df7993bcea7efb7c4fb5085fabebe99535b8f7fdde3c19df54ff
fa08c5cb99 test_runner: Move pruning back to extended (MarcoFalke)
Pull request description:
This reverts fafb55e2c2b257efd4e584f72adf62401c01d573, since the test is still too slow to run with asan enabled on a network hdd
ACKs for commit fa08c5:
jnewbery:
utACK fa08c5cb993f07fd4309f2a6bd9ef4696f07e24c
jonasschnelli:
utACK fa08c5cb993f07fd4309f2a6bd9ef4696f07e24c
Tree-SHA512: de16786b9d507a72210805c3e9eef360e5fc3d4bc3a81f7175b6cc70d1bc426cde7ac97bc0d1a0d4e0813067e1e251c2dd49256552cc6b52446b475251b7c32b
d8bc47fde4 depends: switch to secure download of all dependencies (Ulrich Kempken)
Pull request description:
Even if we potentially check the integrity of the downloaded file via hash comparison, we should make use of SSL since it is available.
ACKs for commit d8bc47:
jonasschnelli:
utACK d8bc47fde46ca0711fa54a0d70ff5d066c708e50
practicalswift:
utACK d8bc47fde46ca0711fa54a0d70ff5d066c708e50
dongcarl:
tACK d8bc47fde46ca0711fa54a0d70ff5d066c708e50
Tree-SHA512: e47702f6d243ed7f498ca84c193244382f16f08df6a297caa224b4468f501f3da6fe542fcf3a0dd9c24ab1b0b38bbc51478068e6006a92854ded23abf90de3c8
df0e97ccb1 RPC: Hint for importmulti in help output of importpubkey and importaddress (Kristaps Kaupe)
Pull request description:
Similar to #12702. Hint for `importmulti` also in help output of `importpubkey` and `importaddress`.
ACKs for commit df0e97:
promag:
utACK df0e97ccb13a28825a2731b95d2bb17f355f6920.
jonasschnelli:
utACK df0e97ccb13a28825a2731b95d2bb17f355f6920
Tree-SHA512: db7358d7f4d463a50874e605bbca35a1a40dbefbb1d35cf51fe2f2aa34bef90c3ca398f4ffbcb9d7d43887a03eb8d81b6ef59066a3c7eda18a7eea876f6592e7
fa69c3e6ca71800376761e264320c363f072dc2f util: Explain why the path is cached (MarcoFalke)
Pull request description:
The rationale for caching the datadir is given as
```
// This can be called during exceptions by LogPrintf(), so we cache the
// value so we don't have to do memory allocations after that.
```
Since 8c2d695c4a45bdd9378c7970b0fcba6e1efc01f9, the debug log location is actually cached itself in `m_file_path`.
So explain that the caching is now only used to guard against disk access on each call. (See also #16255)
ACKs for top commit:
promag:
ACK fa69c3e6ca71800376761e264320c363f072dc2f.
laanwj:
ACK fa69c3e6ca71800376761e264320c363f072dc2f
ryanofsky:
utACK fa69c3e6ca71800376761e264320c363f072dc2f. Good cleanup. Previous comment was confusing, and definitely not helpful if outdated.
Tree-SHA512: 02108c90026d6d7c02843aaf59a06b4e1fa63d5d4378bb7760f50767efc340dc94c259bf7afb32fa4d47952b48a4e91798d1e0ddc1b051d770405e078636793a
f466c4ce846000b2f984b4759f89f3f793fa0100 Add missing ECC_Stop(); in GUI rpcnestedtests.cpp (Jonas Schnelli)
Pull request description:
Fixes#16288
Was probably missing in #7783
ACKs for top commit:
Sjors:
ACK f466c4c. Tested by comparing `make check` on master and this PR with macOS 10.14.5. I also tried with and without `--enable-debug` / `--without-gui`.
fanquake:
ACK f466c4ce846000b2f984b4759f89f3f793fa0100. Tested running `make check` on macOS.
Tree-SHA512: 648e10c2e35bd01fb92e63709169a6c185ac4b62c69af0109d2cd2d7db47e56ae804c788f9a1a1845746f818764799732f9e58e9dbfca3bffeea8f14683c8c7f
f724f31401b963c75bd64f5e2c5b9d9561a9a9dd Make AbortNode() aware of MSG_NOPREFIX flag (Hennadii Stepanov)
96fd4ee02f6c3be21cade729b95a85c60634b0f8 Add MSG_NOPREFIX flag for user messages (Hennadii Stepanov)
f0641f274ffe94fbe7cae43c07a9373013739df2 Prepend the error/warning prefix for GUI messages (Hennadii Stepanov)
Pull request description:
The "Error" prefix/title is set already in the next functions:
- `noui_ThreadSafeMessageBox()`2068f089c8/src/noui.cpp (L17)
- `ThreadSafeMessageBox()`a720a98301/src/qt/bitcoingui.cpp (L1351)
Currently on master:
With this PR:
ACKs for top commit:
laanwj:
concept and code-review ACK f724f31401b963c75bd64f5e2c5b9d9561a9a9dd
Tree-SHA512: 218a179b81cc2ac64239d833c02b4c4d4da9b976728a2dcd645966726c4c660b6f1fe43aa28f33d1cb566785a4329e7f93bf5a502bf202316db79d2ff5fce0f8
fabc57e07dc34c103552cb51c9277bb48ef97739 test: Log to debug.log in all tests (MarcoFalke)
fa4a04a5a942d582c62773d815c7e1e9897975d0 test: use common setup in gui tests (MarcoFalke)
fad3d2a624377de4b0311e6ddd446c36dafd1ddc test: Create data dir in BasicTestingSetup (MarcoFalke)
Pull request description:
This makes it easier to debug a frozen test or a test that failed. To debug a failed test, remove the line `fs::remove_all(m_path_root);`.
The pull is done in three commits:
* Create a datadir for every unit test once (and only once). This requires the `SetDataDir` function to go away.
* Use the common setup in the gui unit tests. Some of those tests are testing the init sequence, so we'd have to undo some of what the testing setup did.
* Log to the debug.log in all tests
ACKs for top commit:
laanwj:
ACK fabc57e07dc34c103552cb51c9277bb48ef97739
Tree-SHA512: 73444210b88172669e2cd22c2703a1e30e105185d2d5f03decbdedcfd09c64ed208d3716c59c8bebb0e44214cee5c8095e3e995d049e1572ee98f1017e413665
a2aabfb749198bce896c9e597082acd67d3b863e Use qInfo() if no error occurs (Hennadii Stepanov)
Pull request description:
[Warning and Debugging Messages](https://doc.qt.io/qt-5/debug.html#warning-and-debugging-messages):
> - `qInfo()` is used for informational messages.
> - `qWarning()` is used to report warnings and recoverable errors in your
application.
>
> If the `QT_FATAL_WARNINGS` environment variable is set, `qWarning()` exits after printing the warning message. This makes it easy to obtain a backtrace in the debugger.
[`qWarning()`](https://doc.qt.io/qt-5/qtglobal.html#qWarning):
> Calls the message handler with the warning message message... This function does nothing if `QT_NO_WARNING_OUTPUT` was defined during compilation; it exits if at the nth warning corresponding to the counter in environment variable `QT_FATAL_WARNINGS`.
This PR allows more productive debugging using the environment variable `QT_FATAL_WARNINGS`.
Examples:
- https://github.com/bitcoin/bitcoin/pull/16118#issuecomment-503184695
- https://github.com/bitcoin/bitcoin/pull/16254#issuecomment-504223404
The behavior, when option `-debug=qt` is set/unset, remains unchanged.
ACKs for commit a2aabf:
promag:
ACK a2aabfb, I also have this change locally.
Empact:
ACK a2aabfb749
laanwj:
ACK a2aabfb749198bce896c9e597082acd67d3b863e
fanquake:
ACK a2aabfb749198bce896c9e597082acd67d3b863e.
Tree-SHA512: b4df300c9c00a1705b0d3a10227e3deaac19a98b0a898bb60d5a88872cf450fb131eba150d9dd6c29e021566ee04b3b86b7d486bbe28bd894743c128d2309155
