From 5e28c0c94157b4d02a854904855f13d31d74db97 Mon Sep 17 00:00:00 2001
From: younies <younies@chromium.org>
Date: Tue, 16 Jun 2020 20:14:44 +0200
Subject: [PATCH] fix findAndMerge function

---
 icu4c/source/i18n/measunit_extra.cpp | 20 ++++++++++----------
 icu4c/source/i18n/unitconverter.cpp  |  6 ++++--
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/icu4c/source/i18n/measunit_extra.cpp b/icu4c/source/i18n/measunit_extra.cpp
index 3f1891ac75a..f7ed5b9d295 100644
--- a/icu4c/source/i18n/measunit_extra.cpp
+++ b/icu4c/source/i18n/measunit_extra.cpp
@@ -769,15 +769,16 @@ MeasureUnit MeasureUnit::product(const MeasureUnit& other, UErrorCode& status) c
     return std::move(impl).build(status);
 }
 
+namespace {
 /**
- * Searches the `simplifiedUnits` for a unit with the same base identifier and the same SI prefix.
- * For example, `square-meter` and `cubic-meter` but not `meter` and `centimeter`.
- * After that, the matched units will be merged.
+ * Searches the `simplifiedUnits` for a unit with the same base identifier and the same SI prefix
+ * (For example, `square-meter` and `cubic-meter` but not `meter` and `centimeter`). After that, the
+ * matched units will be merged. Otherwise, the `newUnitImpl` will be appended.
  */
 void findAndMerge(MeasureUnitImpl &simplifiedUnitsImpl, const SingleUnitImpl &newUnitImpl,
                   UErrorCode &status) {
     for (int i = 0, n = simplifiedUnitsImpl.units.length(); i < n; i++) {
-        auto& singleSimplifiedUnitImpl = *(simplifiedUnitsImpl.units[i]);
+        auto &singleSimplifiedUnitImpl = *(simplifiedUnitsImpl.units[i]);
         if (singleSimplifiedUnitImpl.identifier == newUnitImpl.identifier &&
             singleSimplifiedUnitImpl.siPrefix == newUnitImpl.siPrefix) {
 
@@ -785,9 +786,9 @@ void findAndMerge(MeasureUnitImpl &simplifiedUnitsImpl, const SingleUnitImpl &ne
             return;
         }
     }
-
-    simplifiedUnitsImpl.units.emplaceBackAndCheckErrorCode(status, newUnitImpl);
+    simplifiedUnitsImpl.append(newUnitImpl, status);
 }
+} // namespace
 
 MeasureUnit MeasureUnit::simplify(UErrorCode &status) const {
     if (this->getComplexity(status) == UMeasureUnitComplexity::UMEASURE_UNIT_MIXED) {
@@ -797,10 +798,9 @@ MeasureUnit MeasureUnit::simplify(UErrorCode &status) const {
 
     MeasureUnitImpl resultImpl;
 
-    int32_t outCount;
-    auto singleUnits = this->splitToSingleUnits(outCount, status);
-    for (int i = 0; i < outCount; ++i) {
-        findAndMerge(resultImpl, SingleUnitImpl::forMeasureUnit(singleUnits[i], status), status);
+    const auto &units = (*MeasureUnitImpl::get(*this)).units;
+    for (int i = 0, n = units.length(); i < n; ++i) {
+        findAndMerge(resultImpl, *units[i], status);
     }
 
     return std::move(resultImpl).build(status);
diff --git a/icu4c/source/i18n/unitconverter.cpp b/icu4c/source/i18n/unitconverter.cpp
index f73113ab9c5..dd4cc202106 100644
--- a/icu4c/source/i18n/unitconverter.cpp
+++ b/icu4c/source/i18n/unitconverter.cpp
@@ -495,8 +495,10 @@ double UnitConverter::convert(double inputValue) const {
         result = 1.0 / result;
     }
 
-    // Multiply the result by 1.000,000,001 to fix the deterioration from using `double`
-    // TODO: remove the multiplication by 1.000,000,001 after using `decNumber`
+    // TODO: remove the multiplication by 1.000,000,000,001 after using `decNumber`
+
+    // Multiply the result by 1.000,000,000,001 to fix the deterioration from using `double` (the
+    // deterioration is around 15 to 17 decimal digit).
     return result * 1.000000000001;
 }
 
-- 
2.40.0