ICU-23112 Add check for avoid underflow in MeasureUnit::getIdentifier

wooffie · wooffie · commit 44622e3a3599 · 2025-04-24T10:49:40.000+03:00
diff --git a/icu4c/source/i18n/measunit.cpp b/icu4c/source/i18n/measunit.cpp
@@ -2650,7 +2650,13 @@ const char *MeasureUnit::getSubtype() const {
 }
 
 const char *MeasureUnit::getIdentifier() const {
-    return fImpl ? fImpl->identifier.data() : gSubTypes[getOffset()];
+    if (fImpl){
+        return fImpl->identifier.data();
+    } else if  (fTypeId < 0 || fSubTypeId < 0) {
+        return "";
+    } else {
+        return gSubTypes[getOffset()];
+    }
 }
 
 bool MeasureUnit::operator==(const UObject& other) const {

Original file line number	Diff line number	Diff line change
`@@ -2650,7 +2650,13 @@ const char *MeasureUnit::getSubtype() const {`
`2650`	`2650`	`}`
`2651`	`2651`
`2652`	`2652`	`const char *MeasureUnit::getIdentifier() const {`
`2653`		`- return fImpl ? fImpl->identifier.data() : gSubTypes[getOffset()];`
	`2653`	`+ if (fImpl){`
	`2654`	`+ return fImpl->identifier.data();`
	`2655`	`+ } else if (fTypeId < 0 \|\| fSubTypeId < 0) {`
	`2656`	`+ return "";`
	`2657`	`+ } else {`
	`2658`	`+ return gSubTypes[getOffset()];`
	`2659`	`+ }`
`2654`	`2660`	`}`
`2655`	`2661`
`2656`	`2662`	`bool MeasureUnit::operator==(const UObject& other) const {`