This lets ‘./configure; make’ work on Fedora 36 x86-64 from a Git checkout without generating false-alarm warnings. * lib-src/etags.c (main): There appeared to be false alarm with GCC 12. However, the code was wrong anyway, as it mishandled file names containing "'" so fix that bug. This pacifies GCC. (mercury_decl): Omit tests ‘s + pos != NULL’ that were apparently intended to be ‘s[pos] != '\0'’ but which were miscoded to always be true and which were mostly not needed anyway. In one place, though, a test was needed, so fix that by using strchr instead. * src/alloc.c (lisp_free) [!GC_MALLOC_CHECK]: * src/term.c (Fsuspend_tty): Don’t look at a pointer after freeing it, even just to test it for equality with some other pointer, as this has undefined behavior in C and GCC 12 diagnoses this. * src/dbusbind.c (xd_read_message_1): Rework the code a bit so that it has fewer tests. This pacifies GCC 12 which was complaining incorrectly about dereferencing a null pointer. * src/intervals.c (copy_properties): Remove an eassume that should no longer be needed even to pacify older GCCs, due to ... * src/intervals.h (split_interval_left): ... this addition of ATTRIBUTE_RETURNS_NONNULL to pacify a GCC 12 warning about dereferencing a null pointer. * src/regex-emacs.c (EXTEND_BUFFER): Use negative values rather than auxiliary booleans to indicate null pointers. This pacifies GCC 12 false alarms about using uninitialized variables. * src/xdisp.c (clear_position): New function. (append_space_for_newline, extend_face_to_end_of_line): Use it to work around false alarms from GCC 12. (display_and_set_cursor): Add an UNINIT to pacify GCC 12. * src/xterm.c (x_draw_glyphless_glyph_string_foreground): Defend against hypothetical bad code elsewhere; this also pacifies GCC 12. (x_term_init): Use fixed-size auto array rather than alloca, as the array is small; this also pacifies GCC 12.