TIFF/tif_print.c:282: suspicious for loop ?

[dcb314]

TIFF/tif_print.c:282:30: warning: variable 'i' used in loop condition not modified in loop body [-Wfor-loop-analysis]

Source code is

           for (cp = td->td_inknames; i > 0; cp = strchr(cp, '\0')) {
                    fprintf(fd, "%s%s", sep, cp);
                    sep = ", ";
            }

[nrnhines]

Thanks. Clearly an error. Dates back to the original source. But it is not clear to me what the proper fix is. Is cp a pointer to a list of chars that contains possibly many '\0'? But cp would never increment past the first.

[dcb314]

Still broken nearly four years later.

[nrnhines]

I know nothing, (next to nothing?), about TIFF.

Searching for libtiff.c I found many versions, some with the above bug. One that is very similar to the above but with a fix is
https://git.acem.ece.illinois.edu/lib/VTK-5.0.0/src/commit/1a1c91536bf442bb3d17be57dfdb6a8bd37838cc/Utilities/vtktiff/tif_print.c starting at line 268

        if (TIFFFieldSet(tif,FIELD_INKNAMES)) {
                char* cp;
                fprintf(fd, "  Ink Names: ");
                i = td->td_samplesperpixel;
                sep = "";
                for (cp = td->td_inknames; i > 0; cp = strchr(cp,'\0')+1, i--) {
                        fprintf(fd, "%s", sep);
                        _TIFFprintAscii(fd, cp);
                        sep = ", ";
                }
        }

and another at https://android.googlesource.com/platform/external/free-image/+/71163caf89862f79f6419077cf6f0b18b7725d52/Source/LibTIFF/tif_print.c starting at line 342 that is also very similar and an extra line at the end

		char* cp;
		fprintf(fd, "  Ink Names: ");
		i = td->td_samplesperpixel;
		sep = "";
		for (cp = td->td_inknames; i > 0; cp = strchr(cp,'\0')+1, i--) {
			fputs(sep, fd);
			_TIFFprintAscii(fd, cp);
			sep = ", ";
		}
                fputs("\n", fd);
	}

Github has a very large number of libtiff repositories. One that struck me as undergoing active development is
https://gitlab.com/libtiff/libtiff and
https://gitlab.com/libtiff/libtiff/-/blob/master/libtiff/tif_print.c has the fragment at line 404 (at least a family resemblance in code)

    if (TIFFFieldSet(tif, FIELD_INKNAMES))
    {
        char *cp;
        uint16_t i;
        fprintf(fd, "  Ink Names: ");
        i = td->td_samplesperpixel;
        sep = "";
        for (cp = td->td_inknames;
             i > 0 && cp < td->td_inknames + td->td_inknameslen;
             cp = strchr(cp, '\0') + 1, i--)
        {
            size_t max_chars = td->td_inknameslen - (cp - td->td_inknames);
            fputs(sep, fd);
            _TIFFprintAsciiBounded(fd, cp, max_chars);
            sep = ", ";
        }
        fputs("\n", fd);
    }

I wonder if the simplest fix above fixes your issue?

[dcb314]

I wonder if the simplest fix above fixes your issue?

I am wondering why this project wants to copy out of date source code.

Perhaps linking to the latest version would be a better idea ?