1 files changed, 37 insertions, 0 deletions
diff --git a/external/icu/do-not-reset-useful-cache-to-empty-in-populateNear.patch.2 b/external/icu/do-not-reset-useful-cache-to-empty-in-populateNear.patch.2
new file mode 100644
index 000000000..bd7fe74fb
--- /dev/null
+++ b/external/icu/do-not-reset-useful-cache-to-empty-in-populateNear.patch.2
@@ -0,0 +1,37 @@
+From 34b2f7174ba187d99dfb8704b9cf19d369accc13 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Lubo=C5=A1=20Lu=C5=88=C3=A1k?= <l.lunak@centrum.cz>
+Date: Wed, 16 Mar 2022 10:54:03 +0100
+Subject: [PATCH] do not reset useful cache to empty in populateNear()
+
+---
+ icu4c/source/common/rbbi_cache.cpp | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/icu4c/source/common/rbbi_cache.cpp b/icu4c/source/common/rbbi_cache.cpp
+index 26d82df781..54a77c97c6 100644
+--- a/icu/source/common/rbbi_cache.cpp
++++ b/icu/source/common/rbbi_cache.cpp
+@@ -352,7 +352,7 @@ UBool RuleBasedBreakIterator::BreakCache
+     if ((position < fBoundaries[fStartBufIdx] - 15) || position > (fBoundaries[fEndBufIdx] + 15)) {
+         int32_t aBoundary = 0;
+         int32_t ruleStatusIndex = 0;
+-        if (position > 20) {
++        if (position > 20 && false) { // handleSafePrevious() is broken and always returns 0
+             int32_t backupPos = fBI->handleSafePrevious(position);
+ 
+             if (backupPos > 0) {
+@@ -376,7 +376,10 @@ UBool RuleBasedBreakIterator::BreakCache::populateNear(int32_t position, UErrorC
+                 ruleStatusIndex = fBI->fRuleStatusIndex;
+             }
+         }
+-        reset(aBoundary, ruleStatusIndex);        // Reset cache to hold aBoundary as a single starting point.
++        // Reset cache to hold aBoundary as a single starting point.
++        // Do not do so if what's in the cache is still more useful than an empty cache.
++        if (!(aBoundary == 0 && position > fBoundaries[fEndBufIdx]))
++            reset(aBoundary, ruleStatusIndex);
+     }
+ 
+     // Fill in boundaries between existing cache content and the new requested position.
+-- 
+2.34.1
+