From dfe9d8ea2f39900d128917d0e88414fb9cd34563 Mon Sep 17 00:00:00 2001
From: Olly Betts <olly@survex.com>
Date: Thu, 21 Nov 2024 16:39:18 +1300
Subject: [PATCH] [Java] Fix regression wrapping enum values

Fix regression wrapping enum values which don't fit in a Java signed
int.

Fixes #3070
---
 CHANGES.current                     |  4 ++++
 Examples/test-suite/enum_thorough.i | 16 +++++++++++++++-
 Source/Modules/java.cxx             | 20 +++++++++++++++++++-
 3 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/CHANGES.current b/CHANGES.current
index c7e1a4cfe..f652ea5e8 100644
--- a/CHANGES.current
+++ b/CHANGES.current
@@ -7,6 +7,10 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.4.0 (in progress)
 ===========================
 
+2024-11-21: olly
+	    [Java] #3070 Fix regression wrapping enum values which don't fit
+	    in a Java signed int.
+
 2024-11-09: wsfulton
             #3064 Perform repeated typedef lookups instead of a single typedef
             lookup on the type being applied in %apply when looking for a family
diff --git a/Examples/test-suite/enum_thorough.i b/Examples/test-suite/enum_thorough.i
index e71806cee..15d98af11 100644
--- a/Examples/test-suite/enum_thorough.i
+++ b/Examples/test-suite/enum_thorough.i
@@ -578,6 +578,14 @@ enumWithMacro enumWithMacroTest(enumWithMacro e) { return e; }
 }
 %}
 
+#ifdef SWIGCSHARP
+// It seems these never worked for SWIG/C#.
+%ignore global_typeunsigned1;
+%ignore global_typeunsigned2;
+%ignore global_typeunsigned3;
+%ignore global_typeunsigned4;
+#endif
+
 %inline %{
 namespace DifferentSpace {
 enum DifferentTypes {
@@ -600,7 +608,13 @@ enum {
   global_typechar = 'C',
   global_typedefaultint,
   global_typecharcompound='A'+1,
-  global_typecharcompound2='B' << 2
+  global_typecharcompound2='B' << 2,
+  // Regression tests for #3070 affecting SWIG/Java, introduced in 4.3.0:
+  global_typeunsigned1 = 0x80000000,
+  global_typeunsigned2 = 0xffffffff,
+  // These should also work in > 4.3.0.
+  global_typeunsigned3 = 2147483648,
+  global_typeunsigned4 = 4294967295
 };
 int globalDifferentTypesTest(int n) { return n; }
 }
diff --git a/Source/Modules/java.cxx b/Source/Modules/java.cxx
index b28e71006..9f6edf71d 100644
--- a/Source/Modules/java.cxx
+++ b/Source/Modules/java.cxx
@@ -1424,7 +1424,25 @@ public:
       }
     } else {
       String *numval = Getattr(n, "enumnumval");
-      if (numval) Setattr(n, "enumvalue", numval);
+      if (numval) {
+	const char *p = Char(numval);
+	if (isdigit(p[0])) {
+	  char *e;
+	  unsigned long long value = strtoull(p, &e, 0);
+	  if (errno != ERANGE && *e == '\0' && value >= 0x80000000) {
+	    // Use hex for larger unsigned integer constants in Java code since
+	    // Java allows implicit conversion to a signed integer value.
+	    String *hexval = NewStringf("0x%llx", value);
+	    Setattr(n, "enumvalue", hexval);
+	    Delete(hexval);
+	  } else {
+	    Setattr(n, "enumvalue", numval);
+	  }
+	} else {
+	  // Emit negative values as-is.
+	  Setattr(n, "enumvalue", numval);
+	}
+      }
     }
 
     {