It's fixed in gcc 5.5.0.
Example: https://godbolt.org/z/x6Th8q844
Seen in gcc 5.1.0, 5.4.0 (both 32/64-bit) with dl-mingw:
```
lib/rtsp.c: In function 'rtsp_parse_transport':
lib/rtsp.c:1025:36: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
rtp_channel_mask[idx] |= (unsigned char)(1 << off);
^
lib/mprintf.c: In function 'parsefmt':
lib/mprintf.c:526:31: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
usedinput[width/8] |= (unsigned char)(1 << (width&7));
^
lib/mprintf.c:544:35: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
usedinput[precision/8] |= (unsigned char)(1 << (precision&7));
^
lib/mprintf.c:559:29: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
usedinput[param/8] |= (unsigned char)(1 << (param&7));
^
lib/cfilters.c: In function 'Curl_pollset_change':
lib/cfilters.c:935:25: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
ps->actions[i] |= (unsigned char)add_flags;
^
```
gcc 5.1.0: https://github.com/curl/curl/actions/runs/13413103492/job/37467698381#step:9:21
gcc 5.4.0: https://github.com/curl/curl/actions/runs/13413103492/job/37467694479#step:9:19Closes#16398
ee3f657607