From cdf52396dcdc6ae3a0002d219c34494aab54c51e Mon Sep 17 00:00:00 2001
From: Frank Tang <ftang@chromium.org>
Date: Mon, 17 Mar 2025 21:41:05 -0700
Subject: [PATCH] ICU-22817 Fix memory leak in basictz by using LocalPointer

See https://github.com/LuMingYinDetect/icu_defects/blob/main/icu_1.png
---
 icu4c/source/i18n/basictz.cpp | 39 ++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/icu4c/source/i18n/basictz.cpp b/icu4c/source/i18n/basictz.cpp
index 610a31ad5dc..65a9e87a1e9 100644
--- a/icu4c/source/i18n/basictz.cpp
+++ b/icu4c/source/i18n/basictz.cpp
@@ -140,8 +140,8 @@ BasicTimeZone::getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
     int32_t initialRaw, initialDst;
     UnicodeString initialName;
 
-    AnnualTimeZoneRule *ar1 = nullptr;
-    AnnualTimeZoneRule *ar2 = nullptr;
+    LocalPointer<AnnualTimeZoneRule> ar1;
+    LocalPointer<AnnualTimeZoneRule> ar2;
     UnicodeString name;
 
     UBool avail;
@@ -179,8 +179,8 @@ BasicTimeZone::getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
             // zone to return wrong offset after the transition.
             // When we encounter such case, we do not inspect next next
             // transition for another rule.
-            ar1 = new AnnualTimeZoneRule(name, initialRaw, tr.getTo()->getDSTSavings(),
-                dtr, year, AnnualTimeZoneRule::MAX_YEAR);
+            ar1.adoptInstead(new AnnualTimeZoneRule(name, initialRaw, tr.getTo()->getDSTSavings(),
+                dtr, year, AnnualTimeZoneRule::MAX_YEAR));
 
             if (tr.getTo()->getRawOffset() == initialRaw) {
                 // Get the next next transition
@@ -200,8 +200,8 @@ BasicTimeZone::getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
                         // Generate another DOW rule
                         dtr = new DateTimeRule(month, weekInMonth, dow, mid, DateTimeRule::WALL_TIME);
                         tr.getTo()->getName(name);
-                        ar2 = new AnnualTimeZoneRule(name, tr.getTo()->getRawOffset(), tr.getTo()->getDSTSavings(),
-                            dtr, year - 1, AnnualTimeZoneRule::MAX_YEAR);
+                        ar2.adoptInstead(new AnnualTimeZoneRule(name, tr.getTo()->getRawOffset(), tr.getTo()->getDSTSavings(),
+                            dtr, year - 1, AnnualTimeZoneRule::MAX_YEAR));
 
                         // Make sure this rule can be applied to the specified date
                         avail = ar2->getPreviousStart(date, tr.getFrom()->getRawOffset(), tr.getFrom()->getDSTSavings(), true, d);
@@ -209,13 +209,12 @@ BasicTimeZone::getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
                                 || initialRaw != tr.getTo()->getRawOffset()
                                 || initialDst != tr.getTo()->getDSTSavings()) {
                             // We cannot use this rule as the second transition rule
-                            delete ar2;
-                            ar2 = nullptr;
+                            ar2.adoptInstead(nullptr);
                         }
                     }
                 }
             }
-            if (ar2 == nullptr) {
+            if (ar2.isNull()) {
                 // Try previous transition
                 avail = getPreviousTransition(date, true, tr);
                 if (avail) {
@@ -234,23 +233,21 @@ BasicTimeZone::getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
 
                         // second rule raw/dst offsets should match raw/dst offsets
                         // at the given time
-                        ar2 = new AnnualTimeZoneRule(name, initialRaw, initialDst,
-                            dtr, ar1->getStartYear() - 1, AnnualTimeZoneRule::MAX_YEAR);
+                        ar2.adoptInstead(new AnnualTimeZoneRule(name, initialRaw, initialDst,
+                            dtr, ar1->getStartYear() - 1, AnnualTimeZoneRule::MAX_YEAR));
 
                         // Check if this rule start after the first rule after the specified date
                         avail = ar2->getNextStart(date, tr.getFrom()->getRawOffset(), tr.getFrom()->getDSTSavings(), false, d);
                         if (!avail || d <= nextTransitionTime) {
                             // We cannot use this rule as the second transition rule
-                            delete ar2;
-                            ar2 = nullptr;
+                            ar2.adoptInstead(nullptr);
                         }
                     }
                 }
             }
-            if (ar2 == nullptr) {
+            if (ar2.isNull()) {
                 // Cannot find a good pair of AnnualTimeZoneRule
-                delete ar1;
-                ar1 = nullptr;
+                ar1.adoptInstead(nullptr);
             } else {
                 // The initial rule should represent the rule before the previous transition
                 ar1->getName(initialName);
@@ -278,13 +275,13 @@ BasicTimeZone::getSimpleRulesNear(UDate date, InitialTimeZoneRule*& initial,
     initial = new InitialTimeZoneRule(initialName, initialRaw, initialDst);
 
     // Set the standard and daylight saving rules
-    if (ar1 != nullptr && ar2 != nullptr) {
+    if (ar1.isValid() && ar2.isValid()) {
         if (ar1->getDSTSavings() != 0) {
-            dst = ar1;
-            std = ar2;
+            dst = ar1.orphan();
+            std = ar2.orphan();
         } else {
-            std = ar1;
-            dst = ar2;
+            std = ar1.orphan();
+            dst = ar2.orphan();
         }
     }
 }