Fix a number of leaks in the UI_dup_* functions

If any of general_allocate_{prompt,string,boolean}() fail, the
UI_dup_* functions may leak the strings they strduped beforehand.
Instead, use strdup inside these functions, so we can free as
necessary.  This makes the UI_add_* and UI_dup_* simple wrappers
around general_allocate_{string,boolean}() that differ only in
passing a Boolean that indicates whether or not to use strdup.

Make a general cleanup pass over these functions, simplify the
logic and make it overall a bit easier to follow.  While there,
use strcspn() instead of a handrolled variant.

The only changes in behavior are that ERR_R_MALLOC_FAILURE is now
pushed onto the stack a bit more often and that UI_dup_input_string()
now returns -1 on failure to dup prompt like all the other UI_dup_*
functions.  This is not a problem since the manual already documents
that errors are signaled with <= 0. The only consumer of this function
according to Debian's codesearch is libp11, I sent them a PR to fix
their (already broken) error handling.

Addresses about 10 errors thrown by the LLVM static analyzer in ui/.

ok jsing

0 files changed, 0 insertions, 0 deletions