Various locale mismatch scenarios in Windows clipboard text format synthesis

Summary

So far, we’ve learned that the conversion between Unicode and the 8-bit ANSI and OEM code pages is performed with the assistance of the CF_LOCALE clipboard format, which itself comes from the active keyboard layout. We left with the question of whether this is the right thing, giving as an example the case of highlighting some text in Hebrew and copying it to the clipboard. Shouldn’t that be set with a Hebrew LCID? First of all, you have to specify what you mean by “copy it to the clipboard.” Suppose the English-language user selected some Hebrew text and the program set it to the clipboard as CF_UNICODE­TEXT with a Hebrew LCID. A program which reads the CF_UNICODE­TEXT will read the original Unicode text, with Hebrew characters intact. The LCID plays no role since no conversion was performed. So in the case where the string was placed as Unicode and retrieved as Unicode, everything is fine. If the string were placed as Unicode but read as CF_TEXT, the retrieving program will get the string translated to code page 1252, since that is the ANSI code page used by the US-English LCID. Is this the correct code page? Well, if the retrieving program is using CF_TEXT, then it is a program that uses the 8-bit ANSI character set as its string encoding, and if you’re running on a US-English system, then the 8-bit ANSI character set is code page 1252. So translating the Hebrew text to ANSI via code page 1252 is correct. You need to translate the string into the ANSI code page that the retrieving program is using. Conversely, if the Hebrew string were placed on the clipboard as 8-bit ANSI in code page 1252, then… wait, that’s a trick question! Code page 1252 doesn’t have any Hebrew characters! If a program uses the US-English 8-bit ANSI character set, it cannot represent Hebrew characters at all, so the scenario itself is flawed: There can’t be any Hebrew text on the screen to be selected since the program has no way of displaying it. Now, I guess it could be possible if a progr...