From ca185cf5a14b16d61814d7172284bc8efcd28b69 Mon Sep 17 00:00:00 2001 From: practicalswift Date: Wed, 29 Apr 2020 15:01:02 +0000 Subject: doc: Document differences in bitcoind and bitcoin-qt locale handling --- test/lint/lint-locale-dependence.sh | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'test/lint') diff --git a/test/lint/lint-locale-dependence.sh b/test/lint/lint-locale-dependence.sh index e2bb403c4d..0b839824d5 100755 --- a/test/lint/lint-locale-dependence.sh +++ b/test/lint/lint-locale-dependence.sh @@ -4,6 +4,39 @@ # file COPYING or http://www.opensource.org/licenses/mit-license.php. export LC_ALL=C + +# Be aware that bitcoind and bitcoin-qt differ in terms of localization: Qt +# opts in to POSIX localization by running setlocale(LC_ALL, "") on startup, +# whereas no such call is made in bitcoind. +# +# Qt runs setlocale(LC_ALL, "") on initialization. This installs the locale +# specified by the user's LC_ALL (or LC_*) environment variable as the new +# C locale. +# +# In contrast, bitcoind does not opt in to localization -- no call to +# setlocale(LC_ALL, "") is made and the environment variables LC_* are +# thus ignored. +# +# This results in situations where bitcoind is guaranteed to be running +# with the classic locale ("C") whereas the locale of bitcoin-qt will vary +# depending on the user's environment variables. +# +# An example: Assuming the environment variable LC_ALL=de_DE then the +# call std::to_string(1.23) will return "1.230000" in bitcoind but +# "1,230000" in bitcoin-qt. +# +# From the Qt documentation: +# "On Unix/Linux Qt is configured to use the system locale settings by default. +# This can cause a conflict when using POSIX functions, for instance, when +# converting between data types such as floats and strings, since the notation +# may differ between locales. To get around this problem, call the POSIX function +# setlocale(LC_NUMERIC,"C") right after initializing QApplication, QGuiApplication +# or QCoreApplication to reset the locale that is used for number formatting to +# "C"-locale." +# +# See https://doc.qt.io/qt-5/qcoreapplication.html#locale-settings and +# https://stackoverflow.com/a/34878283 for more details. + KNOWN_VIOLATIONS=( "src/bitcoin-tx.cpp.*stoul" "src/bitcoin-tx.cpp.*trim_right" -- cgit v1.2.3