Also, don't use mblen() directly, to not get stuck when it returns -1,
which it will when running a non-UTF-8 build in a UTF-8 locale.
This fixes https://savannah.gnu.org/bugs/?56472.
Bug existed since commit cd094822 from yesterday.
The majority of characters in the files that get edited with nano will
be single-byte printable ASCII characters, so their case should come
first in the main loop of display_string().
In addition, the function was used just once, had a weird return value,
and now some more code can be excluded from a non-UTF8 build.
Make use of the fact that any single-byte character always occupies
just one column, and call the costly mbtowc() and wcwidth() only for
characters that actually are multibyte.
Instead of calling in twenty places parse_mbchar(pointer, NULL, NULL),
use a simpler and faster char_length(pointer). This saves pushing two
unneeded parameters onto the stack, avoids two needless ifs, and elides
an intermediate variable.
Its main purpose will follow in a later commit: to speed up searching.
This function is used in get_totsize(), so speed is important.
There is no reason why the length of the string must limited to a
certain size -- that is just a leftover from the function merge in
commit ba2e6f43 from a year ago.
The use of a double dash (for an option name or as sentence separator)
is too common to allow it to be seen always as a comment introducer.
Users of Lua and Postgres will have to redefine 'quotestr' themselves
if they want to be able to rewrap block comments with ^J.
The other characters that were added in commit c5a72103 (!, %, and ;)
are less problematic because they tend to be glued to the end of words,
so they are unlikely to appear at the start of a line.
This fixes https://savannah.gnu.org/bugs/?56462,
and fixes https://savannah.gnu.org/bugs/?56461.
Bug existed since version 4.0, commit c5a72103.
There is no need to make a copy of the line, because if there are some
bytes that are moved, they are always moved toward the left -- the line
can only shrink, never expand.
When squeezing excess spaces from a line has proved unsuccessful, we
have already copied all of its data, so it hardly makes a difference
whether we free the old or the new data. Choose to free always the
old data, so that we can simplify things.
Instead of saying that string parameters should be enclosed in
double quotes, just show the quotes in the relevant commands.
Also, rename the parameters, to better fit the subsequent description.
This "holder" information is needed for every cut and paste and other
block operation. Instead of allocating and freeing it for every such
operation, just have the six elements as static variables. This saves
a little churn, and saves having to declare a type that is used just
once. Plus, the access to these variables will be a little quicker.
