V523. The 'then' statement is equivalent to the 'else' statement

The analyzer found a case when the true and false statements of the 'if' operator coincide completely. This often signals a logical error.

Here is an example:

if (X)
  Foo_A();
else
  Foo_A();

Whether the X condition is false or true, the Foo_A() function will be called anyway.

This is the correct version of the code:

if (X)
  Foo_A();
else
  Foo_B();

Here is an example of such an error taken from a real application:

if (!_isVertical)
  Flags |= DT_BOTTOM;
else
  Flags |= DT_BOTTOM;

Presence of two empty statements is considered correct and safe. You might often see such constructs when using macros. This is a sample of safe code:

if (exp) {
} else {
}

Also the analyzer thinks that it is suspicious, if the 'if' statement does not contain the 'else' block, and the code written next is identical to the conditional statement block. At the same time, this code block ends with a return, break, etc.

Suspicious code snippet:

if (X)
{
  doSomething();
  Foo_A();
  return;
}
doSomething();
Foo_A();
return;

Perhaps the programmer forgot to edit the copied code fragment or wrote excessive code.

You can look at examples of errors from real projects which were detected by this diagnostic message.

Do you make errors in the code?

Check your code
with PVS-Studio

Static code analysis
for C, C++ and C#

goto PVS-Studio;