qt: Fix random segfault when closing "Choose data directory" dialog

The `pickDataDirectory()` function was calling `exit(0)` to quit
the application when the user closes the dialog without choosing
a data directory.

This is a bad idea because a background thread is created (to
check free space on the drive of the currently selected datadir).
The thread is not stopped and unwound properly, resulting in a potential
race condition somewhere deep in Qt.

So replace the `exit()` by a boolean return value, and let the
stack unwind normally.
This commit is contained in:
Wladimir J. van der Laan 2016-08-18 16:58:04 +02:00
parent 8250de1358
commit b4a9aa511c
3 changed files with 10 additions and 5 deletions

View file

@ -578,7 +578,8 @@ int main(int argc, char *argv[])
/// 5. Now that settings and translations are available, ask user for data directory
// User language is set up: pick a data directory
Intro::pickDataDirectory();
if (!Intro::pickDataDirectory())
return 0;
/// 6. Determine availability of data directory and parse bitcoin.conf
/// - Do not call GetDataDir(true) before this step finishes

View file

@ -165,14 +165,14 @@ QString Intro::getDefaultDataDirectory()
return GUIUtil::boostPathToQString(GetDefaultDataDir());
}
void Intro::pickDataDirectory()
bool Intro::pickDataDirectory()
{
namespace fs = boost::filesystem;
QSettings settings;
/* If data directory provided on command line, no need to look at settings
or show a picking dialog */
if(!GetArg("-datadir", "").empty())
return;
return true;
/* 1) Default data directory for operating system */
QString dataDir = getDefaultDataDirectory();
/* 2) Allow QSettings to override default dir */
@ -190,7 +190,7 @@ void Intro::pickDataDirectory()
if(!intro.exec())
{
/* Cancel clicked */
exit(0);
return false;
}
dataDir = intro.getDataDirectory();
try {
@ -211,6 +211,7 @@ void Intro::pickDataDirectory()
*/
if(dataDir != getDefaultDataDirectory())
SoftSetArg("-datadir", GUIUtil::qstringToBoostPath(dataDir).string()); // use OS locale for path setting
return true;
}
void Intro::setStatus(int status, const QString &message, quint64 bytesAvailable)

View file

@ -35,10 +35,13 @@ public:
/**
* Determine data directory. Let the user choose if the current one doesn't exist.
*
* @returns true if a data directory was selected, false if the user cancelled the selection
* dialog.
*
* @note do NOT call global GetDataDir() before calling this function, this
* will cause the wrong path to be cached.
*/
static void pickDataDirectory();
static bool pickDataDirectory();
/**
* Determine default data directory for operating system.