Fix lifetime issue: short ternary must also take its else property if…

… not bottom.

build.sh

@@ -61,7 +61,7 @@ FLAGS="$FLAGS -file-id-output build/fileIdPins"
 # see generation.md
 NEXT=compiler$(($($NEAT -print-generation) + 1))
 $NEAT $FLAGS -backend=c -macro-backend=c -next-generation -P$NEXT:src -j src/main.nt \
-    -o build/neat_stage1
+    -version=firstpass -o build/neat_stage1
 cat build/fileIdPins -<<EOF > build/neat.ini
 -syspackage compiler:src
 -running-compiler-version=$TAG

src/neat/statements.nt

@@ -394,10 +394,13 @@ Statement sequence(Statement left, nullable Statement right)
 }
 
 Statement sequence2(nullable Statement first, Statement second) {
-    // TODO this has a lifetime bug
-    // return first?.(sequence(that, second)) else second;
-    if (auto first = first) return sequence(first, second);
-    return second;
+    // TODO remove
+    version (firstpass) {
+        if (auto first = first) return first.(sequence(that, second));
+        return second;
+    } else {
+        return first?.(sequence(that, second)) else second;
+    }
 }
 
 class StatementExpression : Expression

src/neat/ternary.nt

@@ -55,9 +55,10 @@ class ASTTernaryIf : ASTSymbol
          * else { result = else_; }
          */
         auto lifetimeThen = then if elseIsBottom else then.take(context, __RANGE__)?;
+        auto lifetimeElse = else_ if elseIsBottom else else_.take(context, __RANGE__)?;
         auto thenConvert = expectImplicitConvertTo(
             context, lifetimeThen, mergedType, this.locRange)?;
-        auto elseConvert = expectImplicitConvertTo(context, else_, mergedType, this.locRange)?;
+        auto elseConvert = expectImplicitConvertTo(context, lifetimeElse, mergedType, this.locRange)?;
         // If else is bottom, we can just use the lifetime of `then` directly.
         auto lifetime = then.info.lifetime if elseIsBottom else Lifetime.gifted;
         auto result = new PairedTemporary(mergedType, lifetime, context.getUniqueId);

test/runnable/lifetime.nt

@@ -601,9 +601,9 @@ void test_either_replace()
     assert(trace == "-S0 -T0 -U0");
 }
 
-void test_else_prop()
+void test_short_ternary()
 {
-    dbg("- else property");
+    dbg("- short ternary");
     {
         string trace;
         {
@@ -619,6 +619,16 @@ void test_else_prop()
         test? else new C(S("S", &trace, 0));
         assert(trace == "+S1 -S0 -S1");
     }
+    {
+        string trace;
+        {
+            (int | :else) test = :else;
+            auto c = new C(S("S", &trace, 0));
+            test? else c;
+            assert(trace == "+S1 -S0");
+        }
+        assert(trace == "+S1 -S0 -S1");
+    }
     {
         string trace;
         (int | :else) test = 0;
@@ -1189,7 +1199,7 @@ void main()
     test_class_member_ref;
     test_either_member;
     test_either_replace;
-    test_else_prop;
+    test_short_ternary;
     test_error_prop;
     test_array_cat;
     test_statement_expr;