cpp: Add support for multiple keysigs in edit

* lang/cpp/src/gpgsignkeyeditinteractor.cpp
(GpgSignKeyEditInteractor::setDupeOk): New.
(makeTable): Add new tansitions.
(SignKeyState): Add DUPE_OK Status.
(GpgSignKeyEditInteractor::action): Handle DUPE_OK.
(GpgSignKeyEditInteractor::Private::Private): Carry flag.

--
When extended-edit is enabled this can be used to answer
the "dupe_ok" query from the edit-key with yes.

This is for:
GnuPG-Bug-Id: T4734

NEWS

@@ -3,8 +3,15 @@ Noteworthy changes in version 1.14.0 (unreleased)
 
  * New context flag "extended-edit" to enable expert key edit. [#4734]
 
+ * cpp: Add convenience API to obtain remarks. [#4734]
+
+ * cpp: The sign key edit-interactor now supports multiple signatures
+   from the same key. [#4734]
+
  * Interface changes relative to the 1.13.1 release:
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ cpp: UserID::remark                          NEW.
+ cpp: GpgSignKeyEditInteractor::setDupeOk     NEW.
 
 
 Noteworthy changes in version 1.13.1 (2019-06-13)

lang/cpp/src/gpgsignkeyeditinteractor.cpp

@@ -64,6 +64,7 @@ public:
     std::vector<unsigned int> userIDs;
     std::vector<unsigned int>::const_iterator currentId, nextId;
     unsigned int checkLevel;
+    bool dupeOk;
 
     const char *command() const
     {
@@ -126,7 +127,8 @@ GpgSignKeyEditInteractor::Private::Private()
     userIDs(),
     currentId(),
     nextId(),
-    checkLevel(0)
+    checkLevel(0),
+    dupeOk(false)
 {
 }
 
@@ -159,6 +161,7 @@ enum SignKeyState {
     SET_TRUST_REGEXP,
     CONFIRM,
     CONFIRM2,
+    DUPE_OK,
     QUIT,
     SAVE,
     ERROR = EditInteractor::ErrorState
@@ -193,6 +196,7 @@ static GpgSignKeyEditInteractor_Private::TransitionMap makeTable()
     addEntry(SET_CHECK_LEVEL, GET_BOOL, "sign_uid.okay", CONFIRM);
     addEntry(SET_EXPIRE, GET_BOOL, "sign_uid.class", SET_CHECK_LEVEL);
     addEntry(CONFIRM, GET_BOOL, "sign_uid.local_promote_okay", CONFIRM);
+    addEntry(DUPE_OK, GET_BOOL, "sign_uid.okay", CONFIRM);
     addEntry(CONFIRM, GET_BOOL, "sign_uid.okay", CONFIRM);
     addEntry(CONFIRM2, GET_BOOL, "sign_uid.okay", CONFIRM);
     addEntry(CONFIRM, GET_LINE, "keyedit.prompt", COMMAND);
@@ -205,6 +209,7 @@ static GpgSignKeyEditInteractor_Private::TransitionMap makeTable()
     addEntry(UIDS_LIST_SEPARATELY_DONE, GET_LINE, "sign_uid.expire", SET_EXPIRE);
     addEntry(UIDS_LIST_SEPARATELY_DONE, GET_LINE, "sign_uid.class", SET_CHECK_LEVEL);
     addEntry(UIDS_LIST_SEPARATELY_DONE, GET_BOOL, "sign_uid.okay", CONFIRM);
+    addEntry(UIDS_LIST_SEPARATELY_DONE, GET_BOOL, "sign_uid.dupe_okay", DUPE_OK);
     addEntry(CONFIRM, GET_LINE, "keyedit.prompt", QUIT);
     addEntry(ERROR, GET_LINE, "keyedit.prompt", QUIT);
     addEntry(QUIT, GET_BOOL, "keyedit.save.okay", SAVE);
@@ -236,6 +241,8 @@ const char *GpgSignKeyEditInteractor::action(Error &err) const
         return nullptr;
     case SET_CHECK_LEVEL:
         return check_level_strings[d->checkLevel];
+    case DUPE_OK:
+        return answer(d->dupeOk);
     case CONFIRM2:
     case CONFIRM:
         return answer(true);
@@ -326,3 +333,9 @@ void GpgSignKeyEditInteractor::setSigningOptions(int options)
     assert(!d->started);
     d->options = options;
 }
+
+void GpgSignKeyEditInteractor::setDupeOk(bool value)
+{
+    assert(!d->started);
+    d->dupeOk = value;
+}

lang/cpp/src/gpgsignkeyeditinteractor.h

@@ -52,6 +52,11 @@ public:
     void setUserIDsToSign(const std::vector<unsigned int> &userIDsToSign);
     void setSigningOptions(int options);
 
+    /* Set this if it is ok to overwrite an existing signature. In that
+     * case the context has to have the flag "extended-edit" set to 1 through
+     * Context::setFlag before calling edit.*/
+    void setDupeOk(bool value);
+
 private:
     const char *action(Error &err) const override;
     unsigned int nextState(unsigned int statusCode, const char *args, Error &err) const override;