From e8f3d5c65700e53a235507f9e0882a6ca5fe2a71 Mon Sep 17 00:00:00 2001
From: Fredrik Roubert <roubert@google.com>
Date: Fri, 21 Aug 2020 00:16:23 +0200
Subject: [PATCH] ICU-21035 Replace backward compatibility ulocimp_getCountry()
 overload.

By always calling the dynamic memory allocation implementation directly
instead, the fixed memory buffer boundary gets pushed one step further
towards the edges.
---
 icu4c/source/common/loclikely.cpp |  3 +--
 icu4c/source/common/uloc.cpp      | 26 +++++++++++---------------
 icu4c/source/common/ulocimp.h     |  6 +++---
 3 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/icu4c/source/common/loclikely.cpp b/icu4c/source/common/loclikely.cpp
index 41a12352bf..94a60aba3e 100644
--- a/icu4c/source/common/loclikely.cpp
+++ b/icu4c/source/common/loclikely.cpp
@@ -509,8 +509,7 @@ parseTagString(
         }    
     }
 
-    subtagLength = ulocimp_getCountry(position, region, *regionLength, &position);
-    u_terminateChars(region, *regionLength, subtagLength, err);
+    subtagLength = ulocimp_getCountry(position, &position, *err).extract(region, *regionLength, *err);
 
     if(U_FAILURE(*err)) {
         goto error;
diff --git a/icu4c/source/common/uloc.cpp b/icu4c/source/common/uloc.cpp
index 5acf312ed3..95e17d3bce 100644
--- a/icu4c/source/common/uloc.cpp
+++ b/icu4c/source/common/uloc.cpp
@@ -1215,7 +1215,7 @@ ulocimp_getScript(const char *localeID,
     return result;
 }
 
-static CharString
+CharString U_EXPORT2
 ulocimp_getCountry(const char *localeID,
                    const char **pEnd,
                    UErrorCode &status) {
@@ -1250,14 +1250,6 @@ ulocimp_getCountry(const char *localeID,
     return result;
 }
 
-U_CFUNC int32_t
-ulocimp_getCountry(const char *localeID,
-                   char *country, int32_t countryCapacity,
-                   const char **pEnd) {
-    ErrorCode status;
-    return ulocimp_getCountry(localeID, pEnd, status).extract(country, countryCapacity, status);
-}
-
 /**
  * @param needSeparator if true, then add leading '_' if any variants
  * are added to 'variant'
@@ -1458,7 +1450,10 @@ uloc_openKeywords(const char* localeID,
         }
         /* Skip the Country */
         if (_isIDSeparator(*tmpLocaleID)) {
-            ulocimp_getCountry(tmpLocaleID+1, NULL, 0, &tmpLocaleID);
+            ulocimp_getCountry(tmpLocaleID+1, &tmpLocaleID, *status);
+            if (U_FAILURE(*status)) {
+                return 0;
+            }
             if(_isIDSeparator(*tmpLocaleID)) {
                 _getVariant(tmpLocaleID+1, *tmpLocaleID, NULL, 0);
             }
@@ -1750,8 +1745,6 @@ uloc_getCountry(const char* localeID,
             int32_t countryCapacity,
             UErrorCode* err)
 {
-    int32_t i=0;
-
     if(err==NULL || U_FAILURE(*err)) {
         return 0;
     }
@@ -1778,10 +1771,10 @@ uloc_getCountry(const char* localeID,
             localeID = scriptID;
         }
         if(_isIDSeparator(*localeID)) {
-            i=ulocimp_getCountry(localeID+1, country, countryCapacity, NULL);
+            return ulocimp_getCountry(localeID+1, NULL, *err).extract(country, countryCapacity, *err);
         }
     }
-    return u_terminateChars(country, countryCapacity, i, err);
+    return u_terminateChars(country, countryCapacity, 0, err);
 }
 
 U_CAPI int32_t  U_EXPORT2
@@ -1827,7 +1820,10 @@ uloc_getVariant(const char* localeID,
         /* Skip the Country */
         if (_isIDSeparator(*tmpLocaleID)) {
             const char *cntryID;
-            ulocimp_getCountry(tmpLocaleID+1, NULL, 0, &cntryID);
+            ulocimp_getCountry(tmpLocaleID+1, &cntryID, *err);
+            if (U_FAILURE(*err)) {
+                return 0;
+            }
             if (cntryID != tmpLocaleID+1) {
                 /* Found optional country */
                 tmpLocaleID = cntryID;
diff --git a/icu4c/source/common/ulocimp.h b/icu4c/source/common/ulocimp.h
index 279f177f39..8879b2bc2a 100644
--- a/icu4c/source/common/ulocimp.h
+++ b/icu4c/source/common/ulocimp.h
@@ -59,10 +59,10 @@ ulocimp_getScript(const char *localeID,
                   const char **pEnd,
                   UErrorCode &status);
 
-U_CFUNC int32_t
+icu::CharString U_EXPORT2
 ulocimp_getCountry(const char *localeID,
-                   char *country, int32_t countryCapacity,
-                   const char **pEnd);
+                   const char **pEnd,
+                   UErrorCode &status);
 
 U_STABLE void U_EXPORT2
 ulocimp_getName(const char* localeID,