Merge remote-tracking branch 'origin/topic/vern/id-redecl'

* origin/topic/vern/id-redecl:
  fixes for re-declaring type identifiers in inconsistent ways - addresses GH-2686

CHANGES

@@ -1,3 +1,7 @@
+8.1.0-dev.621 | 2025-09-30 20:46:27 +0000
+
+  * GH-2686: fixes for re-declaring type identifiers in inconsistent ways - addresses GH-2686 (Vern Paxson, Corelight)
+
 8.1.0-dev.619 | 2025-09-30 20:45:19 +0000
 
   * Fix for standalone initializations that require BiFs, and streamlining of standalone BiF-tracking (Vern Paxson, Corelight)

VERSION

@@ -1 +1 @@
-8.1.0-dev.619
+8.1.0-dev.621

src/Var.cc

@@ -348,6 +348,35 @@ extern ExprPtr add_and_assign_local(IDPtr id, ExprPtr init, ValPtr val) {
 }
 
 void add_type(ID* id, TypePtr t, std::unique_ptr<std::vector<AttrPtr>> attr) {
+    if ( const auto& old_t = id->GetType() ) {
+        // The identifier already has a type associated with it. This can
+        // be okay if (1) it's already been marked as a Type identifier,
+        // (2) the previous type is a stub, or an equivalent enum.
+        if ( ! id->IsType() ) {
+            reporter->Error("Identifier %s has already been declared and is not a type", id->Name());
+            return;
+        }
+
+        if ( old_t->Tag() == t->Tag() && ((old_t->Tag() == TYPE_RECORD && old_t->AsRecordType()->NumFields() == 0) ||
+                                          (t->Tag() == TYPE_ENUM && same_type(t, old_t))) )
+            // It has a consistent tag and is either redeclaring a stub
+            // record (used in init-bare.zeek) or an equivalent enum
+            // (which can appear due to specifiers in BiFs, for example).
+            ;
+
+        else {
+            std::string loc;
+            auto li = id->GetLocationInfo();
+            auto fn = li->FileName();
+            int ln = li->FirstLine();
+            if ( fn && fn[0] != '\0' )
+                loc = " at " + std::string(fn) + ":" + std::to_string(ln);
+
+            reporter->Error("Type %s has already been declared%s", id->Name(), loc.c_str());
+            return;
+        }
+    }
+
     std::string new_type_name = id->Name();
     std::string old_type_name = t->GetName();
 

testing/btest/Baseline/language.redeclaration-redefinition-errors-12/out

@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/redeclaration-redefinition-errors.zeek, line 2: Identifier f has already been declared and is not a type

testing/btest/Baseline/language.redeclaration-redefinition-errors-13/out

@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/redeclaration-redefinition-errors.zeek, line 2: Type f has already been declared at <...>/redeclaration-redefinition-errors.zeek:1

testing/btest/language/redeclaration-redefinition-errors.zeek

@@ -59,3 +59,11 @@ global f: function();
 global f = function() { };
 global f: hook();
 global f: event();
+
+# @TEST-START-NEXT
+global f = function() { };
+type f: bool;
+
+# @TEST-START-NEXT
+type f: record {};
+type f: bool;