This mess goes completely to hell when a reallocation is necessary. Not only is realloc() called with the wrong arguments; sptable was also incremented before (so that it does not point anymore to the allocated memory). And after a realloc, the free(ip) will free the wrong memory.
Welcome to IRAF.
The file
fgwrite.cis obviously buggy in the memory allocation ofslines.slinesis globally defined: https://github.com/iraf-community/fitsutil/blob/a85313c562dd446c2e75f1f8835f971f5354f740/src/fgwrite.c#L112main(argc, argv)https://github.com/iraf-community/fitsutil/blob/a85313c562dd446c2e75f1f8835f971f5354f740/src/fgwrite.c#L269-L272 …toc_card()andlist_mef()is called indirectly https://github.com/iraf-community/fitsutil/blob/a85313c562dd446c2e75f1f8835f971f5354f740/src/fgwrite.c#L303-L306toc_card (in, fh, ftype, hd_cards, level, usize)https://github.com/iraf-community/fitsutil/blob/a85313c562dd446c2e75f1f8835f971f5354f740/src/fgwrite.c#L1463-L1468__
list_mef(fd, usize)__ https://github.com/iraf-community/fitsutil/blob/a85313c562dd446c2e75f1f8835f971f5354f740/src/fgwrite.c#L1585-L1589This mess goes completely to hell when a reallocation is necessary. Not only is
realloc()called with the wrong arguments;sptablewas also incremented before (so that it does not point anymore to the allocated memory). And after a realloc, thefree(ip)will free the wrong memory. Welcome to IRAF.