More gracefully checking that parameter is within bounds

sjoblomj · sjoblomj · commit dbe60e3ad5a7 · 2024-10-16T00:24:38.000+02:00
diff --git a/libs/s25main/postSystem/PostBox.cpp b/libs/s25main/postSystem/PostBox.cpp
@@ -65,7 +65,9 @@ const PostMsg* PostBox::GetMsg(unsigned idx) const
 
 const PostMsg* PostBox::GetCurrentMsg() const
 {
-    unsigned idx = currMsgIdx >= 0 && currMsgIdx < (int) numMessages ? currMsgIdx : numMessages - 1;
+    if(numMessages == 0 || currMsgIdx > static_cast<int>(numMessages) - 1)
+        return nullptr;
+    unsigned idx = currMsgIdx >= 0 ? currMsgIdx : numMessages - 1;
     return GetMsg(idx);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,9 @@ const PostMsg* PostBox::GetMsg(unsigned idx) const`
`65`	`65`
`66`	`66`	`const PostMsg* PostBox::GetCurrentMsg() const`
`67`	`67`	`{`
`68`		`- unsigned idx = currMsgIdx >= 0 && currMsgIdx < (int) numMessages ? currMsgIdx : numMessages - 1;`
	`68`	`+ if(numMessages == 0 \|\| currMsgIdx > static_cast<int>(numMessages) - 1)`
	`69`	`+ return nullptr;`
	`70`	`+ unsigned idx = currMsgIdx >= 0 ? currMsgIdx : numMessages - 1;`
`69`	`71`	`return GetMsg(idx);`
`70`	`72`	`}`
`71`	`73`