raster/vector: EAN/UPC: fix calculation of image/vector height to

allow for heights smaller than `textoffset` when have add-on
  (buffer overflow for raster, outside vector height for vector)
raster: EAN/UPC: make sure don't overwrite add-on stuff when
  line-copying guard descenders by limiting copy width
ZBarcode_Encode_Segs: allow for multiple (stacked) rows when
  setting absolute minimum height;
  state stacked symbols max in error message
DBAR_EXP: check length on encoding method 6 before trying to parse
  3-digit currency string with `z_to_int()`
CLI: stop looping over data args when have error;
  suppress taint warning by using fixed `malloc()` size for
  `arg_opts` instead of `argc`
general: use `vsnprintf()` instead of `vsprintf()` if not C89
ULTRACODE: don't call `ult_generate_codewords()` if `length` 0
  from fragment processing (avoids `assert()`)
clang-tidy -> 23 & suppress some warnings
test suite: fuzz: leave Z_FUZZ_DEBUG to compiler, fix comment
general: some minor code-formatting on touched files
README.deb -> README.debian (avoid confusion with actual ".deb")
BWIPP: update to latest

backend/ultra.c

@@ -810,6 +810,8 @@ static int ult_generate_codewords_segs(struct zint_symbol *symbol, struct zint_s
        Note not updating `eci` for GS1 mode as not converted */
     const int content_segs = !gs1 && (symbol->output_options & BARCODE_CONTENT_SEGS);
 
+    assert(length > 0); /* Suppress clang-tidy-23 clang-analyzer-core.uninitialized.Assign */
+
     for (i = 0; i < seg_count; i++) {
         if (segs[i].eci) {
             have_eci = 1;
@@ -908,8 +910,10 @@ static int ult_generate_codewords_segs(struct zint_symbol *symbol, struct zint_s
     }
 
     current_mode = symbol_mode;
-    codeword_count = ult_generate_codewords(symbol, source, length, 0 /*eci*/, gs1, symbol_mode, &current_mode,
-                                            codewords, codeword_count);
+    if (length > 0) {
+        codeword_count = ult_generate_codewords(symbol, source, length, 0 /*eci*/, gs1, symbol_mode, &current_mode,
+                                                codewords, codeword_count);
+    }
     if (content_segs && segs[0].eci) {
         z_ct_set_seg_eci(symbol, 0, segs[0].eci);
     }