cpp: Fix Key::canSign()

* lang/cpp/src/key.h (canReallySign): Deprecate.
* lang/cpp/src/key.cpp (canSign): Remove workaround. Use implementation
of canReallySign.
(canReallySign): Use canSign().
(operator<<): Use canSign().
--

The workaround in canSign was added 19 years ago and canReallySign, the
workaround for the workaround, was added 13 years ago. Time to get rid
of those workarounds for a bug in gpgme which has been fixed long ago
and which cause bugs for any unsuspecting user of Key::canSign().

GnuPG-bug-id: 6456

2 files changed, 4 insertions, 17 deletions

diff --git a/lang/cpp/src/key.cpp b/lang/cpp/src/key.cpp
index b7a55aec..b18cfaee 100644
--- a/lang/cpp/src/key.cpp
+++ b/lang/cpp/src/key.cpp
@@ -208,17 +208,12 @@ bool Key::canEncrypt() const
 
 bool Key::canSign() const
 {
-#ifndef GPGME_CAN_SIGN_ON_SECRET_OPENPGP_KEYLISTING_NOT_BROKEN
-    if (key && key->protocol == GPGME_PROTOCOL_OpenPGP) {
-        return true;
-    }
-#endif
-    return canReallySign();
+    return key && key->can_sign;
 }
 
 bool Key::canReallySign() const
 {
-    return key && key->can_sign;
+    return canSign();
 }
 
 bool Key::canCertify() const
@@ -1297,7 +1292,7 @@ std::ostream &operator<<(std::ostream &os, const Key &key)
            << "\n issuer:     " << protect(key.issuerName())
            << "\n fingerprint:" << protect(key.primaryFingerprint())
            << "\n listmode:   " << key.keyListMode()
-           << "\n canSign:    " << key.canReallySign()
+           << "\n canSign:    " << key.canSign()
            << "\n canEncrypt: " << key.canEncrypt()
            << "\n canCertify: " << key.canCertify()
            << "\n canAuth:    " << key.canAuthenticate()
diff --git a/lang/cpp/src/key.h b/lang/cpp/src/key.h
index 787cb43e..9e827f63 100644
--- a/lang/cpp/src/key.h
+++ b/lang/cpp/src/key.h
@@ -110,16 +110,8 @@ public:
     bool isBad() const;
 
     bool canEncrypt() const;
-    /*!
-      This function contains a workaround for old gpgme's: all secret
-      OpenPGP keys canSign() == true, which canReallySign() doesn't
-      have. I don't have time to find what breaks when I remove this
-      workaround, but since Kleopatra merges secret into public keys,
-      the workaround is not necessary there (and actively harms), I've
-      added a new function instead.
-     */
     bool canSign() const;
-    bool canReallySign() const;
+    GPGMEPP_DEPRECATED bool canReallySign() const;
     bool canCertify() const;
     bool canAuthenticate() const;
     bool isQualified() const;