ca2a09640fe976b1e74a33d29d9381895e71b347 Change SetType to SetInternal and remove m_address_type (Andrew Chow)
89b1ce1140535b4c902a7c5999bed335b9ddfe7c Remove unimplemented SetCrypted from DescriptorScriptPubKeyMan (Andrew Chow)
b9073c8f13fb0ba94c2ec6365666343e19fd9ddf rpc: createwallet warning that descriptor wallets are experimental (Andrew Chow)
610030d95c60ea526440d801a98ac8bd370eac48 docs: Add release notes for descriptor wallets (Andrew Chow)
Pull request description:
Some docs and cleanup following #16528.
* Added release notes to explain a bit of motivation for descriptor wallets, what was changed, and how users will be effected by it. Also mentions the caveats regarding multsigs and watchonly that we have discussed on IRC.
* Adds a warning to `createwallet` that descriptor wallets are experimental.
* Removed unused `SetCrypted` as suggestioned: https://github.com/bitcoin/bitcoin/pull/16528#discussion_r415300916
* Removed `m_address_type` as mentioned in https://github.com/bitcoin/bitcoin/pull/18782#issuecomment-620167077
ACKs for top commit:
Sjors:
tACK ca2a09640fe976b1e74a33d29d9381895e71b347
instagibbs:
utACK ca2a09640f
meshcollider:
utACK ca2a09640fe976b1e74a33d29d9381895e71b347
Tree-SHA512: 987188a912c191430e5d3f89bcef54ba6773692fc2d95b16a3ec11d9007ded210466ed980a3857e8b7196beef6422f07f9c85cc157f996c02d16f4dbde2e7b2a
1ed52fbb4d81f7b7634fd4fb6d1d00e1478129dc Remove IBD check in sethdseed (Andrew Chow)
b1810a145a601a8064e4094350cfb6ddafbdb4d8 Test that keys from inactive seeds are generated (Andrew Chow)
c93082ece40b1c72f05b3e2085c022c09eaa4d65 Generate new keys for inactive seeds after marking used (Andrew Chow)
45f2f6a0e8514a0438a87554400bf73cbb90707f Determine inactive HD seeds from key metadata and track them in LegacyScriptPubKeyMan (Andrew Chow)
b59b4504abf96cec860badfed2ac793ae5d40ced have GenerateNewKey and DeriveNewChildKey take a CHDChain as an argument (Andrew Chow)
Pull request description:
Largely implements the suggestion from https://github.com/bitcoin/bitcoin/pull/17484#issuecomment-560845316.
After `sethdseed` is called, the CHDChain for the old seed is kept in the wallet. It is kept on the file as a new `inactivehdseed` record and in memory in a map `m_inactive_hd_seeds`. In `LegacyScriptPubKeyMan::MarkUnusedAddresses` we check each used key's metadata for whether it was derived from an inactive seed. If it is, we then check to see how many keys after that key were derived from the inactive seed. If that number does not match the keypool parameter, we derive more keys from the inactive seed until it does match. This way we won't miss transactions belonging to keys outside of the range of the keypool initially.
The indexes and internal-ness of a key is gotten by checking it's key origin data.
Because of this change, we no longer need to wait for IBD to finish before `sethdseed` can work so that check is also removed.
A test case for this is added as well which fails on master.
ACKs for top commit:
ryanofsky:
Code review ACK 1ed52fbb4d81f7b7634fd4fb6d1d00e1478129dc. Changes since last review: various commit message, code comment, log message, error checking improvements, and fix for topping up inactive seeds if wallet isn't reloaded after calling sethdseed and test for this
ariard:
Code Review ACK 1ed52fb
jonatack:
ACK 1ed52fbb4d81f7 thanks for addressing the previous review feedback; would be happy to see the new review questions answered and feedback addressed and re-ack.
Tree-SHA512: e658ae0e1dab94be55d2b62cdda506c94815e73a6881533fd30d41cc77477f82fee2095144957a3a1df0c129e256bdd7b7abe3737d515f393610446cae4edf1c
It is no longer necessary to wait for IBD to be complete before setting
a HD seed. This check was originally to ensure that restoring an old
seed on an out of sync node would scan the entire blockchain and thus
not miss transactions that involved keys that were not in the keypool.
This was necessary as once the seed was changed, no further keys would
be derived from the old seed(s).
As we are now topping up inactive seeds as we find those keys to be
used, this check is no longer necessary. During IBD, each time we
find a used key belonging to an inactive hd seed, we will still generate
more keys from that inactive seed.
fa1f840596554ed264d11ee3b3643bf99eb57eb5 rpcwallet: Replace pwallet-> with wallet. (MarcoFalke)
fa182a8794cbf9be1aa91d1d75e65bc7800156bc rpcwallet: Replace boost::optional<T>::emplace with simple assignment of T{} (MarcoFalke)
Pull request description:
Closes#18943
ACKs for top commit:
laanwj:
ACK fa1f840596554ed264d11ee3b3643bf99eb57eb5
ryanofsky:
Code review ACK fa1f840596554ed264d11ee3b3643bf99eb57eb5 and thanks for using a standalone commit for the fix
promag:
Code review ACK fa1f840596554ed264d11ee3b3643bf99eb57eb5.
hebasto:
ACK fa1f840596554ed264d11ee3b3643bf99eb57eb5, tested on Linux Mint 19.3.
Tree-SHA512: 0838485d1f93f737ce5bf12740669dcafeebb78dbc3fa15dbcc511edce64bf024f60f0497a04149a1e799d893d57b0c9ffe442020c1b9cfc3c69db731f50e712
9f59dde9740d065118bdddde75ef9f4e4603a7b1 rpc: Relock wallet only if most recent callback (João Barbosa)
a2e6db5c4f1bb52a8814102b628e51652493d06a rpc: Add mutex to guard deadlineTimers (João Barbosa)
Pull request description:
This PR fixes an early relocking race condition from #18811 where old relock callback runs after new wallet unlock code and nRelockTime update but before rpcRunLater call, causing early relock and incorrect nRelockTime time
Issue introduced in #18487.
Fixes#18811.
ACKs for top commit:
MarcoFalke:
ACK 9f59dde9740d065118bdddde75ef9f4e4603a7b1
ryanofsky:
Code review ACK 9f59dde9740d065118bdddde75ef9f4e4603a7b1. No changes since last review except squashing commits.
jonatack:
ACK 9f59dde9740d065118bdddde75ef
Tree-SHA512: 2f7fc03e5ab6037337f2d82dfad432495cc337c77d07c968ee2355105db6292f24543c03456f5402e0e759577a4327758f9372f7ea29de6d56dc3695fda9b379
28b112e9bd3fd1181c0720306051ba7efca8b436 Get rid of BindWallet (Russell Yanofsky)
d002f9d15d938e78360ad906f2d74a249c7e923e Disable CWalletTx copy constructor (Russell Yanofsky)
65b9d8f8ddb5a838454efc8bdd6576f0deb65f6d Avoid copying CWalletTx in LoadToWallet (Russell Yanofsky)
bd2fbc7cdbec46400341209f4cb7e69e5b2cee19 Get rid of unneeded CWalletTx::Init parameter (Russell Yanofsky)
2b9cba206594bfbcefcef0c88a0bf793819643bd Remove CWalletTx merging logic from AddToWallet (Russell Yanofsky)
Pull request description:
This is a pure refactoring, no behavior is changing.
Instead of AddToWallet taking a temporary CWalletTx object and then potentially merging it with a pre-existing CWalletTx, have it take a callback so callers can update the pre-existing CWalletTx directly.
This makes AddToWallet simpler because now it is only has to be concerned with saving CWalletTx objects and not merging them.
This makes AddToWallet calls clearer because they can now make direct updates to CWalletTx entries without having to make temporary objects and then worry about how they will be merged.
Motivation for this change came from the bumpfee PR #8456 where we wanted to be able to call AddToWallet to make a simple update to an existing transaction, but were reluctant to, because the existing CWalletTx merging logic did not apply and seemed dangerous try to update as part of that PR. After this refactoring, the bumpfee PR could call AddToWallet safely instead of implementing a duplicate AddToWallet function.
This also allows getting rid of the CWalletTx copy constructor to prevent unintentional copying.
ACKs for top commit:
MarcoFalke:
Anyway, re-ACK 28b112e9bd3fd1181c0720306051ba7efca8b436
Tree-SHA512: 528dd088714472a237500b200f4433db850bdb7fc29c5e5d81cae48072061dfb967f7c37edd90b33f24901239f9be982988547c1f8c80abc25fb243fbf7330ef
Also, mark feebumper bilingual_str as Untranslated
They are technical and have previously not been translated either.
It is questionable whether they can even appear in the GUI.
Common errors and warnings should be translated when displayed in the
GUI, but not translated when displayed elsewhere. The wallet method
CreateWalletFromFile does not know its caller, so this commit changes it
to return a bilingual_str to the caller.
Disable copying of CWalletTx objects to prevent bugs where instances get copied
in and out of the mapWallet map and fields are updated in the wrong copy.
This change is intended to make the bitcoin node and its rpc, network
and gui interfaces more responsive while the wallet is in use. Currently
because the node's cs_main mutex is always locked before the wallet's
cs_wallet mutex (to prevent deadlocks), cs_main currently stays locked
while the wallet does relatively slow things like creating and listing
transactions.
This commit only remmove chain lock tacking in wallet code, and invert
lock order from cs_main, cs_wallet to cs_wallet, cs_main.
must happen at once to avoid any deadlock. Previous commit were only
removing Chain::Lock methods to Chain interface and enforcing they
take cs_main.
Remove LockChain method from CWallet and Chain::Lock interface.
a1d5b12ec07d2f7aa9fa955a6dd99e8a2be5cb25 Merge getreceivedby tally into GetReceived function (Andrew Toth)
Pull request description:
This PR merges the tally code of `getreceivedbyaddress` and `getreceivedbylabel` into a single function `GetReceived`. This reduces repeated code and makes it similar to `listreceivedbyaddress` and `listreceivedbylabel`, which use the function `ListReceived`. It will also make the change in #14707 simpler and easier to review.
ACKs for top commit:
theStack:
re-ACK a1d5b12ec0
meshcollider:
utACK a1d5b12ec07d2f7aa9fa955a6dd99e8a2be5cb25
Tree-SHA512: 43d9cd92f7c2c6a8b9c7509aa85a9b9233a6cfec1c43a9062e3bdfb83515413d1feafa8938c828351278ba22bd31c47e62ab5341e4bddc2493103b094d73b047
0d32d661481f099af572e7a08a50e17bcc165c44 Remove -upgradewallet startup option (Andrew Chow)
92263cce5b6c6b66296dadda5f29724611db0160 Add upgradewallet RPC (Andrew Chow)
1e48796c99b63aa8fa8451ce7b0c20759ea43500 Make UpgradeWallet a member function of CWallet (Andrew Chow)
c988f27937bc79c90f4eed48552c72f1b66dc044 Have UpgradeWallet take the version to upgrade to and an error message out parameter (Andrew Chow)
183323712398e26ddcf3a9dc048aaa9900a91f5a Only run UpgradeWallet if the wallet needs to be upgraded (Andrew Chow)
9c16b1735f8e530ce68d678e9ca0eceb2ceb3520 Move wallet upgrading to its own function (Andrew Chow)
Pull request description:
`-upgradewallet` is largely incompatible with many recent wallet features and versions. For example, it was disabled if multiple wallets were used and would not work with encrypted wallets that were being upgraded to HD.
This PR does away with the old method of upgrading upon startup and instead allows users to upgrade their wallets via an `upgradewallet` RPC. This does largely the same thing as the old `-upgradewallet` option but because the wallet is loaded, it can be unlocked to upgrade to HD. Furthermore it is compatible with multiwallet as it works on the individual wallet that is specified by the RPC.
ACKs for top commit:
meshcollider:
Code review ACK 0d32d661481f099af572e7a08a50e17bcc165c44
darosior:
ACK 0d32d661481f099af572e7a08a50e17bcc165c44
MarcoFalke:
ACK 0d32d661481f099af572e7a08a50e17bcc165c44 🚵
Tree-SHA512: b425bf6f5d605e26506889d63c780895482f07cbc086193218e031e8504d3072d41e90d65cd41bcc98ee4c1eb048954bc5d4ac85435f7394892373aac89a3b0a
fa168d754221a83cab0d2984a02c41cf6819e873 rpc: Document all aliases for first arg of listtransactions (MarcoFalke)
fa5b1f067fcf8bebb23455dd8a16cde5068e79cd rpc: Document all aliases for second arg of getblock (MarcoFalke)
fa86a4bbfc000593ae4ad9dcdaec3fd0c0406086 rpc: Rename first arg of generateblock RPC to "output" (MarcoFalke)
Pull request description:
This fixes a bug found with #18531:
* Currently the named argument for `generateblock` is documented as `address/descriptor`, but the server only accepts a named argument of `address`. Fix it by changing the name to `output` for both the documentation and the server code. Also, add tests to prove the server understands the new name `output`.
* Unrelated to that, there have been a bunch of aliases in the server code that are not present in the source code of the documentation. Fix that by adding the alias to the source code of the documentation. Only the first alias is displayed in the rendered documentation. Also, add tests to prove the server actually understands all aliases.
ACKs for top commit:
pierreN:
Tested ACK fa168d7 tests, help messages
Tree-SHA512: 05e15628e3a667b296f3783d20f764b450b959451b5360c7eaf5993156582d47a0f5882330ca2493b851eb46324d504953b90c875bc88a15c9e8c89eb3ef8d92
38677274f931088218eeb1f258077d3387f39c89 rpc: settxfee respects -maxtxfee wallet setting (Fabian Jahr)
bda84a08a0ac92dff6cadc99cf9bb8c3fadd7e13 rpc: Add documentation for deactivating settxfee (Fabian Jahr)
Pull request description:
~~Closes 18315~~
`settxfee` can be deactivated by passing 0 as the fee. That does not seem to be documented for the user so this PR adds it in the description. The return value of a simple boolean seems also too simplified given the multiple dimensions that this deactivation feature enables. I.e. it does not seem intuitive if the returned boolean shows that the call succeeded or if means that `settxfee` is active. My suggested solution is to change the return value to a JSON object that included the "active" state and the currently set fee rate.
Examples:
```
$ src/bitcoin-cli settxfee 0.0000000
{
"active": false,
"fee_rate": "0.00000000 BTC/kB"
}
$ src/bitcoin-cli settxfee 0.0001
{
"active": true,
"fee_rate": "0.00010000 BTC/kB"
}
```
ACKs for top commit:
MarcoFalke:
ACK 38677274f931088218eeb1f258077d3387f39c89, seems useful to error out early instead of later #16257🕍
jonatack:
ACK 38677274f931088218eeb
meshcollider:
LGTM, utACK 38677274f931088218eeb1f258077d3387f39c89
Tree-SHA512: 642813b5cf6612abb4b6cb63728081a6bd1659d809e0149c8f56060b6da7253fee989b3b202854f3051df3773c966799af30b612648c466b099f00590f356548
48973402d8bccb673eaeb68b7aa86faa39d3cb8a wallet: Avoid use of Chain::Lock in CWallet::GetKeyBirthTimes (Russell Yanofsky)
e958ff9ab5607da2cd321f29fc785a6d359e44f4 wallet: Avoid use of Chain::Lock in CWallet::CreateTransaction (Russell Yanofsky)
c0d07dc4cba7634cde4e8bf586557772f3248a42 wallet: Avoid use of Chain::Lock in CWallet::ScanForWalletTransactions (Russell Yanofsky)
1be8ff280c78c30baabae9429c53c0bebb89c44d wallet: Avoid use of Chain::Lock in rescanblockchain (Russell Yanofsky)
3cb85ac594f115db99f96b0a0f4bfdcd69ef0590 wallet refactor: Avoid use of Chain::Lock in CWallet::RescanFromTime (Russell Yanofsky)
f7ba881bc669451a60fedac58a449794702a3e23 wallet: Avoid use of Chain::Lock in listsinceblock (Russell Yanofsky)
bc96a9bfc61afdb696fb92cb644ed5fc3d1793f1 wallet: Avoid use of Chain::Lock in importmulti (Russell Yanofsky)
25a9fcf9e53bfa94e8f8b19a4abfda0f444f6b2a wallet: Avoid use of Chain::Lock in importwallet and dumpwallet (Russell Yanofsky)
c1694ce6bb7e19a8722d5583cd85ad17da40bb67 wallet: Avoid use of Chain::Lock in importprunedfunds (Russell Yanofsky)
ade5f87971211bc67753f14a0d49e020142efc7c wallet refactor: Avoid use of Chain::Lock in qt wallettests (Russell Yanofsky)
f6da44ccce4cfff53433e665305a6fe0a01364e4 wallet: Avoid use of Chain::Lock in tryGetTxStatus and tryGetBalances (Russell Yanofsky)
bf30cd4922ea62577d7bf63f5029e8be62665d45 refactor: Add interfaces::FoundBlock class to selectively return block data (Russell Yanofsky)
Pull request description:
This is a set of changes updating wallet code to make fewer calls to `Chain::Lock` methods, so the `Chain::Lock` class will be easier to remove in #16426 with fewer code changes and small changes to behavior.
ACKs for top commit:
MarcoFalke:
re-ACK 48973402d8, only change is fixing bug 📀
fjahr:
re-ACK 48973402d8bccb673eaeb68b7aa86faa39d3cb8a, reviewed rebase and changes since last review, built and ran tests locally
ariard:
Coce Review ACK 4897340, only changes are one suggested by last review on more accurate variable naming, human-readable output, args comments in `findCommonAncestor`
Tree-SHA512: cfd2f559f976b6faaa032794c40c9659191d5597b013abcb6c7968d36b2abb2b14d4e596f8ed8b9a077e96522365261299a241a939b3111eaf729ba0c3ef519b
c0af173da20cc4560523205bc268677a808a43df doc: default minconf for getbalance should be 0 (U-Zyn Chua)
Pull request description:
- Default `minconf` for `getbalance` is `0` but example in doc was showing as `1`.
- `at least 6 blocks confirmed` now updated to be `at least 6 confirmations` to be more consistent with the terminology used elsewhere in the codebase and documentations.
ACKs for top commit:
theStack:
re-ACK c0af173da2
Tree-SHA512: 8f67af78a222a4bd2957658b37fae2224783274f355af84f39a5ce0da90b21f03dc798a6408d44a724c353ff5ed7dfec943fb28726ec423028b64fc579f937ad
01a3392b1b778fa4fcf568013326d6ea1de4fb3b Drop bitcoin-wallet dependency on libevent (Russell Yanofsky)
0660119ac372c2863d14060ac1bc9bc243771f94 Drop unintended bitcoin-tx dependency on libevent (Russell Yanofsky)
Pull request description:
This fixes compile errors trying to build bitcoin-tx and bitcoin-wallet without libevent, which were reported by Luke Dashjr in https://github.com/bitcoin/bitcoin/issues/18465
The fix avoiding `bitcoin-tx` dependency on libevent just adds a conditional build rule. This is implemented in the first commit (more details in commit description).
The fix avoiding `bitcoin-wallet` dependency on libevent requires minor code changes, because `bitcoin-wallet` (unlike `bitcoin-tx`) links against code that calls `urlDecode` / `evhttp_uridecode`. This fix is implemented in the second commit (again details in the commit description).
ACKs for top commit:
jonasschnelli:
utACK 01a3392b1b778fa4fcf568013326d6ea1de4fb3b.
Tree-SHA512: d2245e912ab494cccceeb427a1eca8e55b01a0006ff93eebcfb5461ae7cecd1083ac2de443d9db036b18bdc6f0fb615546caaa20c585046f66d234937f74870a
fa1a92224dd78de817d15bcda35a8310254e1a54 rpc: Avoid initialization-order-fiasco on static CRPCCommand tables (MarcoFalke)
Pull request description:
Currently the fiasco is only theoretical because all content of the table are compile-time constants. However, the fiasco materializes should they ever become run-time constants (e.g. #18531).
ACKs for top commit:
promag:
ACK fa1a92224dd78de817d15bcda35a8310254e1a54.
practicalswift:
ACK fa1a92224dd78de817d15bcda35a8310254e1a54 -- fiasco bad :)
Tree-SHA512: cccadb0ad56194599b74f04264d74c34fa865958580a850efc6474bbdc56f30cadce6b2e9a6ad5472ff46c3f4c793366acd8090fad409a45b25d961f2d89da19
b5795a788639305bab86a8b3f6b75d6ce81be083 Wallet: Add warning comments and assert to CWallet::DelAddressBook (Luke Dashjr)
6d2905f57aaeb3ec3b63d31043f7673ca10003f2 Wallet: Avoid unnecessary/redundant m_address_book lookups (Luke Dashjr)
c751d886f499257627b308b11ffaa51c22db6cc0 Wallet: Avoid treating change-in-the-addressbook as non-change everywhere (Luke Dashjr)
8e64b8c84bcbd63caea06f3af087af1f0609eaf5 Wallet: New FindAddressBookEntry method to filter out change entries (and skip ->second everywhere) (Luke Dashjr)
65b6bdc2b164343ec3cc3d32a0297daff9e24fec Wallet: Add CAddressBookData::IsChange which returns true iff label has never been set (Luke Dashjr)
144b2f85da4d51bf7d72b987888ddcaf5b429eed Wallet: Require usage of new CAddressBookData::setLabel to change label (Luke Dashjr)
b86cd155f6f661052042048aa7cfc2a397afe4f7 scripted-diff: Wallet: Rename mapAddressBook to m_address_book (Luke Dashjr)
Pull request description:
In many places, our code assumes that presence in the address book indicates a non-change key, and absence of an entry in mapAddressBook indicates change.
This no longer holds true after #13756 (first released in 0.19) since it added a "used" DestData populated even for change addresses. Only avoid-reuse wallets should be affected by this issue.
Thankfully, populating DestData does not write a label to the database, so we can retroactively fix this (so long as the user didn't see the change address and manually assign it a real label).
Fixing it is accomplished by:
* Adding a new bool to CAddressBookData to track if the label has ever been assigned, either by loading one from the database, or by assigning one at runtime.
* `CAddressBookData::IsChange` and `CWallet::FindAddressBookEntry` are new methods to assist in excluding change from code that doesn't expect to see them.
* For safety in merging, `CAddressBookData::name` has been made read-only (the actual data is stored in `m_label`, a new private member, and can be changed only with `setLabel` which updates the `m_change` flag), and `mapAddressBook` has been renamed to `m_address_book` (to force old code to be rebased to compile).
A final commit also does some minor optimisation, avoiding redundant lookups in `m_address_book` when we already have a pointer to the `CAddressBookData`.
ACKs for top commit:
ryanofsky:
Code review ACK b5795a788639305bab86a8b3f6b75d6ce81be083. Pretty clever and nicely implemented fix!
jonatack:
ACK b5795a788639305bab86a8b3f6b75d6ce81be083 nice improvements -- code review, built/ran tests rebased on current master ff53433fe4ed06893d7c4 and tested manually with rpc/cli
jnewbery:
Good fix. utACK b5795a788.
Tree-SHA512: 40525185a0bcc1723f602243c269499ec86ecb298fecb5ef24d626bbdd5e3efece86cdb1084ad7eebf7eeaf251db4a6e056bcd25bc8457b417fcbb53d032ebf0
7b8e15728d1ad058a4b7d7569fd5d5ba6806ca28 rpc: Fix rpcRunLater race in walletpassphrase (João Barbosa)
Pull request description:
Release locks before calling `rpcRunLater`.
Quick explanation: `rpcRunLater` leads to `event_free` which calls `event_del` which can wait for the event callback to finish if it's already running and that callback will try to lock wallet mutex - which is already locked in http thread.
Fixes#14995 , fixes#18482. Best reviewed with whitespace changes hidden.
ACKs for top commit:
MarcoFalke:
ACK 7b8e15728d, only tested that this avoids the node freezing. Did not look at how libevent works or how the deadlock happens or if this breaks other stuff. 📞
ryanofsky:
Code review ACK 7b8e15728d1ad058a4b7d7569fd5d5ba6806ca28. Just updated comment since last review
Tree-SHA512: 17874a2fa7b0e164fb0d7ee4cb7d59650275b8c03476fb291d60af8b758495457660d3912623fb26259fefe84aeba21c0a9e0c6467982ba511f19344ed5413ab
Previous versions assumed absence of an entry in mapAddressBook indicated change.
This no longer holds true (due to bugs) and will shortly be made intentional.
Renaming the field helps ensure that old code using mapAddressBook directly gets checked for necessary rebasing.
-BEGIN VERIFY SCRIPT-
sed -i -e 's/mapAddressBook/m_address_book/g' $(git grep -l 'mapAddressBook' ./src)
-END VERIFY SCRIPT-
Don't require urlDecode function in wallet code since urlDecode implementation
currently uses libevent. Just call urlDecode indirectly though URL_DECODE
function pointer constant if available.
In bitcoind and bitcoin-qt, URL_DECODE is implemented and used to interpret RPC
wallet requests. In bitcoin-wallet, URL_DECODE is null to avoid depending on
libevent.
