fix(runtime): coverity STRING_NULL #569464 (#34795)

Problem:
Coverity reports string null termination issue:

    *** CID 569464:  Memory - string handling  (STRING_NULL)
    /src/nvim/runtime.c: 1374 in ExpandRTDir_int()
    1372         if (flags & DIP_START) {
    1373           memcpy(tail - 15, "pack/*/start/*/", 15);  // NOLINT
    >>>     CID 569464:  Memory - string handling  (STRING_NULL)
    >>>     Passing unterminated string "tail - 15" to "globpath", which expects a null-terminated string.
    1374           globpath(p_pp, tail - 15, gap, glob_flags, expand_dirs);

    Similar issues occur at lines 1376, 1381, and 1383 where memcpy()
    constructs strings passed to globpath() without null termination.

Solution:
Replace dangerous pointer arithmetic and memcpy() with direct snprintf()
construction of complete search paths. This eliminates the need for
buffer reuse through pointer offsets and ensures all strings passed to
globpath() are properly null-terminated.

vim-patch:9.1.1515: Coverity complains about potential unterminated strings

0 files changed, 0 insertions, 0 deletions