guix/gnu/packages/patches/icu4c-bug-2002735-ICU-23277-coptic-single-era.patch

diff --git a/source/i18n/coptccal.cpp b/source/i18n/coptccal.cpp
--- a/source/i18n/coptccal.cpp
+++ b/source/i18n/coptccal.cpp
@@ -61,46 +61,43 @@ int32_t
 CopticCalendar::handleGetExtendedYear(UErrorCode& status)
 {
     if (U_FAILURE(status)) {
         return 0;
     }
     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
         return internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
     }
-    // The year defaults to the epoch start, the era to CE
-    int32_t era = internalGet(UCAL_ERA, CE);
-    if (era == BCE) {
-        return 1 - internalGet(UCAL_YEAR, 1); // Convert to extended year
-    }
-    if (era == CE){
-        return internalGet(UCAL_YEAR, 1); // Default to year 1
-    }
-    status = U_ILLEGAL_ARGUMENT_ERROR;
-    return 0;
+    // The year defaults to the epoch start
+    return internalGet(UCAL_YEAR, 1); // Default to year 1
 }
 
 IMPL_SYSTEM_DEFAULT_CENTURY(CopticCalendar, "@calendar=coptic")
 
 int32_t
 CopticCalendar::getJDEpochOffset() const
 {
     return COPTIC_JD_EPOCH_OFFSET;
 }
 
 int32_t CopticCalendar::extendedYearToEra(int32_t extendedYear) const {
-    return extendedYear <= 0 ? BCE : CE;
+    return CE;
 }
 
 int32_t CopticCalendar::extendedYearToYear(int32_t extendedYear) const {
-    return extendedYear <= 0 ? 1 - extendedYear : extendedYear;
+    return extendedYear;
 }
 
-bool CopticCalendar::isEra0CountingBackward() const {
-    return true;
+int32_t
+CopticCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const
+{
+    if (field == UCAL_ERA) {
+        return 1; // Only one era, era is always 1
+    }
+    return CECalendar::handleGetLimit(field, limitType);
 }
 
 int32_t
 CopticCalendar::getRelatedYearDifference() const {
     constexpr int32_t kCopticCalendarRelatedYearDifference = 284;
     return kCopticCalendarRelatedYearDifference;
 }
 
diff --git a/source/i18n/coptccal.h b/source/i18n/coptccal.h
--- a/source/i18n/coptccal.h
+++ b/source/i18n/coptccal.h
@@ -165,16 +165,22 @@ protected:
     int32_t getRelatedYearDifference() const override;
 
     /**
      * Return the extended year defined by the current fields.
      * @internal
      */
     virtual int32_t handleGetExtendedYear(UErrorCode& status) override;
 
+    /**
+     * Calculate the limit for a specified type of limit and field
+     * @internal
+     */
+    virtual int32_t handleGetLimit(UCalendarDateFields field, ELimitType limitType) const override;
+
     DECLARE_OVERRIDE_SYSTEM_DEFAULT_CENTURY
 
     /**
      * Return the date offset from Julian
      * @internal
      */
     int32_t getJDEpochOffset() const override;
 
@@ -184,21 +190,16 @@ protected:
      */
     int32_t extendedYearToEra(int32_t extendedYear) const override;
 
     /**
      * Compute the year from extended year.
      * @internal
      */
     int32_t extendedYearToYear(int32_t extendedYear) const override;
-
-    /**
-     * @internal
-     */
-    bool isEra0CountingBackward() const override;
 public:
     /**
      * Override Calendar Returns a unique class ID POLYMORPHICALLY. Pure virtual
      * override. This method is to implement a simple version of RTTI, since not all C++
      * compilers support genuine RTTI. Polymorphic operator==() and clone() methods call
      * this method.
      *
      * @return   The class ID for this object. All objects of a given class have the