Merge #581: Combine terminal variants

211f0cb Combine terminal variants (Tobin C. Harding)

Pull request description:

  We have various variants in this pattern that return the same thing, we can combine them to make the code more terse with no loss of clarity.

ACKs for top commit:
  apoelstra:
    ACK 211f0cb

Tree-SHA512: e61960e3ca0a8dd365a8cf38f3cbf15a6515592c3c1cc92c8abbb3b59ace9af0886a53d2733c8155bdfa712227d9be436f94c8754523a95e31d96b6e78c00330

Author: apoelstra

src/miniscript/satisfy.rs

@@ -1332,15 +1332,11 @@ impl Satisfaction {
                 stack: Witness::empty(),
                 has_sig: false,
             },
-            Terminal::True => Satisfaction {
-                stack: Witness::Impossible,
-                has_sig: false,
-            },
-            Terminal::Older(_) => Satisfaction {
-                stack: Witness::Impossible,
-                has_sig: false,
-            },
-            Terminal::After(_) => Satisfaction {
+            Terminal::True
+            | Terminal::Older(_)
+            | Terminal::After(_)
+            | Terminal::Verify(_)
+            | Terminal::OrC(..) => Satisfaction {
                 stack: Witness::Impossible,
                 has_sig: false,
             },
@@ -1361,10 +1357,6 @@ impl Satisfaction {
                 stack: Witness::push_0(),
                 has_sig: false,
             },
-            Terminal::Verify(_) => Satisfaction {
-                stack: Witness::Impossible,
-                has_sig: false,
-            },
             Terminal::AndV(ref v, ref other) => {
                 let vsat =
                     Self::satisfy_helper(&v.node, stfr, root_has_sig, leaf_hash, min_fn, thresh_fn);
@@ -1406,10 +1398,6 @@ impl Satisfaction {
                     has_sig: rnsat.has_sig || lnsat.has_sig,
                 }
             }
-            Terminal::OrC(..) => Satisfaction {
-                stack: Witness::Impossible,
-                has_sig: false,
-            },
             Terminal::OrI(ref l, ref r) => {
                 let lnsat = Self::dissatisfy_helper(
                     &l.node,