[PATCH] Set behavior of sprintf-like functions with overlapping source and destination

[Joseph Myers]

On Thu, 27 Dec 2018, Siddhesh Poyarekar wrote:

> With this action plan we don't really need to test the undefined behaviour
> since we don't intend to retain it except in the compat case, just flip the

Compat symbol semantics should be tested in the testsuite (with 
appropriate TEST_COMPAT conditionals and use of compat_symbol_reference).  
(There are exceptional cases where the new symbol's semantics are a 
refinement of the old and so the two symbol versions alias each other and 
no separate test of the old version is useful, but a new version is added 
to stop new binaries working with old libc - e.g. when some fenv.h 
functions changed from void to int return type following C99TC1 - but the 
normal case is that the compat symbols should be tested to ensure they 
keep working as expected.)

-- 
Joseph S. Myers
joseph@codesourcery.com