Merge #9718: Qt/Intro: Various fixes

a9baa6d Bugfix: Qt/Intro: Pruned nodes never require *more* space (Luke Dashjr)
93ffba7 Bugfix: Qt/Intro: Chain state needs to be stored even with the full blockchain (Luke Dashjr)
c8cee26 Qt/Intro: Update block chain size (Luke Dashjr)

Author: laanwj

src/qt/intro.cpp

@@ -23,7 +23,7 @@
 
 static const uint64_t GB_BYTES = 1000000000LL;
 /* Minimum free space (in GB) needed for data directory */
-static const uint64_t BLOCK_CHAIN_SIZE = 80;
+static const uint64_t BLOCK_CHAIN_SIZE = 120;
 /* Minimum free space (in GB) needed for data directory when pruned; Does not include prune target */
 static const uint64_t CHAIN_STATE_SIZE = 2;
 /* Total required space (in GB) depending on user choice (prune, not prune) */
@@ -126,8 +126,13 @@ Intro::Intro(QWidget *parent) :
     ui->storageLabel->setText(ui->storageLabel->text().arg(tr(PACKAGE_NAME)));
     uint64_t pruneTarget = std::max<int64_t>(0, GetArg("-prune", 0));
     requiredSpace = BLOCK_CHAIN_SIZE;
-    if (pruneTarget)
-        requiredSpace = CHAIN_STATE_SIZE + std::ceil(pruneTarget * 1024 * 1024.0 / GB_BYTES);
+    if (pruneTarget) {
+        uint64_t prunedGBs = std::ceil(pruneTarget * 1024 * 1024.0 / GB_BYTES);
+        if (prunedGBs <= requiredSpace) {
+            requiredSpace = prunedGBs;
+        }
+    }
+    requiredSpace += CHAIN_STATE_SIZE;
     ui->sizeWarningLabel->setText(ui->sizeWarningLabel->text().arg(tr(PACKAGE_NAME)).arg(requiredSpace));
     startThread();
 }