If `index.html` does not exist in the directory from which the example
is invoked, the fopen(upload, "rb") invocation in `setup` would fail,
returning NULL. This value is subsequently passed as the FILE* argument
of the `fread` invocation in the `read_callback` function, which is the
actual cause of the crash (apparently `fread` assumes that argument to
be non-null).
In addition, mitigate some possible crashes of similar origin.
Closes#5463
When size_t is not a typedef for unsigned long (as usually the case on
Windows), GCC emits -Wformat warnings when using lu and lx format
specifiers with size_t. Silence them with explicit casts to
unsigned long.
Closes https://github.com/curl/curl/pull/2721
All plain C examples now (mostly) adhere to the curl code style. While
they are only examples, they had diverted so much and contained all
sorts of different mixed code styles by now. Having them use a unified
style helps users and readability. Also, as they get copy-and-pasted
widely by users, making sure they're clean and nice is a good idea.
573 checksrc warnings were addressed.
pop3-multi.c:96:5: warning: implicit declaration of function 'memset'
imap-multi.c:96:5: warning: implicit declaration of function 'memset'
http2-download.c:226:5: warning: implicit declaration of function 'memset'
http2-upload.c:290:5: warning: implicit declaration of function 'memset'
http2-upload.c:290:5: warning: implicit declaration of function 'memset'
