Check if Membership::GetPrefixChar() returns 0 before appending it to a string

Spotted by @barosl

4 files changed, 14 insertions, 4 deletions

diff --git a/src/channels.cpp b/src/channels.cpp
index fcfb524ce..c2060b90e 100644
--- a/src/channels.cpp
+++ b/src/channels.cpp
@@ -664,7 +664,9 @@ void Channel::UserList(User *user)
 		Membership* memb = i->second;
 
 		prefixlist.clear();
-		prefixlist.push_back(memb->GetPrefixChar());
+		char prefix = memb->GetPrefixChar();
+		if (prefix)
+			prefixlist.push_back(prefix);
 		nick = i->first->nick;
 
 		FOREACH_MOD(OnNamesListItem, (user, memb, prefixlist, nick));
diff --git a/src/coremods/core_who.cpp b/src/coremods/core_who.cpp
index 670f05a90..2c120e562 100644
--- a/src/coremods/core_who.cpp
+++ b/src/coremods/core_who.cpp
@@ -220,7 +220,11 @@ void CommandWho::SendWhoLine(User* user, const std::vector<std::string>& parms,
 	}
 
 	if (memb)
-		wholine.push_back(memb->GetPrefixChar());
+	{
+		char prefix = memb->GetPrefixChar();
+		if (prefix)
+			wholine.push_back(prefix);
+	}
 
 	wholine.append(" :0 " + u->fullname);
 
diff --git a/src/coremods/core_whois.cpp b/src/coremods/core_whois.cpp
index bd0b624d1..934dd2102 100644
--- a/src/coremods/core_whois.cpp
+++ b/src/coremods/core_whois.cpp
@@ -68,7 +68,9 @@ std::string CommandWhois::ChannelList(User* source, User* dest, bool spy)
 		 */
 		if (spy != (source == dest || !(c->IsModeSet(privatemode) || c->IsModeSet(secretmode)) || c->HasUser(source)))
 		{
-			list.push_back(memb->GetPrefixChar());
+			char prefix = memb->GetPrefixChar();
+			if (prefix)
+				list.push_back(prefix);
 			list.append(c->name).push_back(' ');
 		}
 	}
diff --git a/src/modules/m_check.cpp b/src/modules/m_check.cpp
index ad0e2394d..35901f8d5 100644
--- a/src/modules/m_check.cpp
+++ b/src/modules/m_check.cpp
@@ -194,7 +194,9 @@ class CommandCheck : public Command
 			{
 				Membership* memb = *i;
 				Channel* c = memb->chan;
-				chliststr.push_back(memb->GetPrefixChar());
+				char prefix = memb->GetPrefixChar();
+				if (prefix)
+					chliststr.push_back(prefix);
 				chliststr.append(c->name).push_back(' ');
 			}