base64_digits: reduce scope, implicit zero, +1 size

the array is not accessed outside of base64dec() so it makes sense to
limit it's scope to the related function. the static-storage duration of
the array is kept intact.

this also removes unnecessary explicit zeroing from the start and end of
the array. anything that wasn't explicitly zero-ed will now be
implicitly zero-ed instead.

the validity of the new array can be easily confirmed via running this
trivial loop:

	for (int i = 0; i < 255; ++i)
		assert(base64_digits[i] == base64_digits_old[i]);

lastly, as pointed out by Roberto, the array needs to have 256 elements
in order to able access it as any unsigned char as an index; the
previous array had 255.

however, this array will only be accessed at indexes which are
isprint() || '=' (see `base64dec_getc()`), so reducing the size of the
array to the highest printable ascii char (127 AFAIK) + 1 might also be
a valid strategy.

ref. https://git.suckless.org/st/commit/ef0551932fb162f907b40185d2f48c3b497708ee.html
This commit is contained in:
bakkeby 2022-03-28 11:23:52 +02:00
parent addd5e9749
commit d8ec7a396c
2 changed files with 8 additions and 16 deletions

View file

@ -1,4 +1,4 @@
Similar to [dwm-flexipatch](https://github.com/bakkeby/dwm-flexipatch) this st 0.8.5 (2aefa34, 2022-03-13) project has a different take on st patching. It uses preprocessor directives to decide whether or not to include a patch during build time. Essentially this means that this build, for better or worse, contains both the patched _and_ the original code. The aim being that you can select which patches to include and the build will contain that code and nothing more.
Similar to [dwm-flexipatch](https://github.com/bakkeby/dwm-flexipatch) this st 0.8.5 (ef05519, 2022-03-18) project has a different take on st patching. It uses preprocessor directives to decide whether or not to include a patch during build time. Essentially this means that this build, for better or worse, contains both the patched _and_ the original code. The aim being that you can select which patches to include and the build will contain that code and nothing more.
For example to include the `alpha` patch then you would only need to flip this setting from 0 to 1 in [patches.h](https://github.com/bakkeby/st-flexipatch/blob/master/patches.def.h):
```c