What causes "%s: bogus -crop argument '%s' " in DrKLO/Telegram?

Use the exact format WxH+X+Y, e.g. -crop 100x100+0+0.

%s: bogus -crop argument '%s'

Error message

%s: bogus -crop argument '%s'

What it means

jpegtran's -crop argument failed to parse via jtransform_parse_crop_spec(). The expected format is WxH+X+Y (or WxH+X+Y with optional alignment/offset syntax); an unparseable string triggers this fatal error.

Source

Thrown at TMessagesProj/jni/mozjpeg/jpegtran.c:212

      /* Select which extra markers to copy. */
      if (++argn >= argc)       /* advance to next argument */
        usage();
      if (keymatch(argv[argn], "none", 1)) {
        copyoption = JCOPYOPT_NONE;
      } else if (keymatch(argv[argn], "comments", 1)) {
        copyoption = JCOPYOPT_COMMENTS;
      } else if (keymatch(argv[argn], "all", 1)) {
        copyoption = JCOPYOPT_ALL;
      } else
        usage();

    } else if (keymatch(arg, "crop", 2)) {
      /* Perform lossless cropping. */
#if TRANSFORMS_SUPPORTED
      if (++argn >= argc)       /* advance to next argument */
        usage();
      if (!jtransform_parse_crop_spec(&transformoption, argv[argn])) {
        fprintf(stderr, "%s: bogus -crop argument '%s'\n",
                progname, argv[argn]);
        exit(EXIT_FAILURE);
      }
      prefer_smallest = FALSE;
#else
      select_transform(JXFORM_NONE);    /* force an error */
#endif

    } else if (keymatch(arg, "debug", 1) || keymatch(arg, "verbose", 1)) {
      /* Enable debug printouts. */
      /* On first -d, print version identification */
      static boolean printed_version = FALSE;

      if (!printed_version) {
        fprintf(stderr, "%s version %s (build %s)\n",
                PACKAGE_NAME, VERSION, BUILD);
        fprintf(stderr, "%s\n\n", JCOPYRIGHT);
        fprintf(stderr, "Emulating The Independent JPEG Group's software, version %s\n\n",

View on GitHub (pinned to 45ab8f4308)

Solutions

Use the exact format WxH+X+Y, e.g. -crop 100x100+0+0.
If calling the API, validate the parsed spec fields (width>0, height>0) after jtransform_parse_crop_spec returns nonzero.
Quote the argument to prevent shell globbing/expansion of the '+' or 'x'.
Test the crop string against the parser separately before bundling into a full jpegtran command.

Example fix

// before
./jpegtran -crop 100,100,0,0 in.jpg > out.jpg
// after
./jpegtran -crop 100x100+0+0 in.jpg > out.jpg

Defensive patterns

Strategy: validation

Validate before calling

#include <ctype.h>
/* minimal WxH+X+Y validator matching jtransform_parse_crop_spec expectations */
int crop_spec_ok(const char *s) {
  const char *p = s; char *end;
  long w = strtol(p,&end,10); if (end==p||*end!='x'||w<=0) return 0; p=end+1;
  long h = strtol(p,&end,10); if (end==p||h<=0) return 0; p=end;
  if (*p!='+') return 0; p++;
  long x = strtol(p,&end,10); if (end==p||x<0) return 0; p=end;
  if (*p!='+') return 0; p++;
  long y = strtol(p,&end,10); if (end==p||y<0) return 0; p=end;
  return *p=='\0';
}

Prevention

Build crop strings in the exact WxH+X+Y form.
Validate the spec before passing to jpegtran.
Quote the argument to shield '+' and 'x' from the shell.

When it happens

Trigger: Passing a malformed crop spec such as -crop 100, -crop 100x, -crop x100+0+0, -crop 100x100-0-0, or any string jtransform_parse_crop_spec rejects. Also triggered by missing width/height or invalid delimiters.

Common situations: Constructing the crop string programmatically with a format bug, locale issues affecting 'x' parsing, or copy-pasting a spec from a tool that uses a different syntax.

Related errors

AI-assisted analysis of DrKLO/Telegram@45ab8f4308 (2026-08-14). Data as JSON: /api/errors/001dbd1ad71e4c5c. Report an issue: GitHub.