Wordpad: garbage in dialog when opening Edit>Advanced>Complete Text

reactos-bootcd-0.4.16-dev-254-g30b4024-x86-gcc-lin-dbg

• Open Wordpad
• Do NOT enter any content
• Edit>Advanced>Complete Text
• Shows a first "empty" dialog (expected, as no content)
• then shows a second dialog with some garbage
• Guilty code related to EM_GETTEXTRANGE management: https://git.reactos.org/?p=reactos.git;a=blob;f=base/applications/wordpad/wordpad.c;hb=6aa11ac494ec2cc127196f17247fbb3fb973b86a#l2296 
• Nothing in log