fix(coverity): kv_ensure_space overflow #42091

Problem:
gcc and Coverity report potential `size + len `overflow kv_concat_len().

    CID 656305:         Null pointer dereferences  (FORWARD_NULL)
    /src/nvim/input_cmdatom.c: 474             in atom_push_raw()
    468           atom_captures++;
    469         }
    470         if (collect) {
    471           composite.queued = true;
    472         }
    473         kv_push(vatom.atoms, *atom);
    >>>     CID 656305:         Null pointer dereferences  (FORWARD_NULL)
    >>>     Dereferencing null pointer "cur_frame".
    474         vatom.frame = cur_frame->id;
    475         return;
    476       }
    477       atom_captures++;
    478       if (atom->type == kAVisual && kv_size(atom->atoms) > 0) {
    479         // The completing operator is the only subatom that could have edited.

    CID 656304:         Memory - illegal accesses  (OVERRUN)
    /src/nvim/input.c: 718             in sb_add_spec()
    712     /// bytes. Unlike sb_add_lit(), no CTRL-V: for text read raw (<Cmd>), not typed into a cmdline.
    713     void sb_add_spec(StringBuilder *buf, const char *s)
    714     {
    715       while (*s != NUL) {
    716         if ((uint8_t)(*s) == K_SPECIAL && s[1] != NUL && s[2] != NUL) {
    717           // Insert special key literally.
    >>>     CID 656304:         Memory - illegal accesses  (OVERRUN)
    >>>     Overrunning dynamic array "buf->items" at offset corresponding to index variable "buf->size" through dereference in call to "memcpy".
    718           kv_concat_len(*buf, s, 3);
    719           s += 3;
    720         } else {
    721           sb_add_char(buf, mb_cptr2char_adv(&s));
    722         }
    723       }

Solution:
Both are false positives; assert or check to avoid the warnings.

0 files changed, 0 insertions, 0 deletions