Updating XIM cursor position is expensive, so only update it when cursor position changed.

This entry is intended for monocolor display and it is very helpful for color haters.

St used to use backspace as BS until the commit 230d0c8, but due to general lack of knowledge of lusers, we moved to the most common configuration in linux to avoid answering the same question 3 times per month. With the most common configuration we have a backspace that returns a DEL, and we have a Delete key that doesn't return a DEL character neither a BS. When dealing with devices connected using a serial line (or even with Plan9) it is more common Backspace as BS and Delete as DEL. For this reason, st is not always the best tool when you talk with a serial device. This patch adds new terminfo entries for Backspace as BS and Delete as DEL. A patch for confg.h is also added, to make easier switch between both configurations.

When a read operation returns 0 then it means that we arrived to the end of the file, and new reads will return 0 unless you do some other operation such as lseek(). This case happens with USB-232 adapters when they are unplugged.

Scroll is a program that stores all the lines of its child and be used in st as a way of implementing scrollback. This solution is much better than implementing the scrollback in st itself because having a different program allows to use it in any other program without doing modifications to those programs.

Reported by Aajonus, thanks!

This line didn't work at mshortcuts at config.h: /* mask button function arg release */ { ShiftMask, Button2, selpaste, {.i = 0}, 1 }, and now it does work. The issue was that XButtonEvent.state is "the logical state ... just prior to the event", which means that on release the state has the Button2Mask bit set because button2 was down just before it was released. The issue didn't manifest with the default shift + middle-click on release (to override mouse mode) because its specified modifier is XK_ANY_MOD, at which case match(...) ignores any specific bits and simply returns true. The issue also doesn't manifest on press, because prior to the event Button<N> was not down and its mask bit is not set. Fix by filtering out the mask of the button which we're currently matching. We could have said "well, that's how button events behave, you should use ShiftMask|Button2Mask for release", but this both not obvious to figure out, and specifically here always filtering does not prevent configuring any useful modifiers combination. So it's a win-win.

XCreateIC ICValues default XNFocusWindow to XNClientWindow if not specified, it can be omitted since it is the same. From the documentation https://www.x.org/releases/current/doc/libX11/libX11/libX11.html > Focus Window > > The XNFocusWindow argument specifies the focus window. The primary > purpose of the XNFocusWindow is to identify the window that will receive > the key event when input is composed. > > When this XIC value is left unspecified, the input method will use the > client window as the default focus window.

Do not try to set specific IM method, let the user specify it with XMODIFIERS. If the requested method is not available or opening fails, fallback to the default input handler and register a handler on the new IM server availability signal. Do the same when the input server is closed and (re)started.

Current buffer is too short to input medium to long sentences from IME. Input with longer text will show the wrong input, taking 64 instead of 32 bytes should be enough for most of the cases. Broken cases before, Chinese (taken from song 也可以) 可不可以轻轻的松开自己 Japanese (taken from bootleggers rom quote) あなたは家のように感じる

- add common question about the w3m image drawing hack. - remove some bad advise about $TERM. - change some links to https.

Strings which an application sends to the terminal in OSC, DCS, etc are typically small (title, colors, etc) but one exception is OSC 52 which copies text to the clipboard, and is used for instance by tmux. Previously st cropped these strings at 512 bytes, which for OSC 52 limited the copied text to 382 bytes (remaining buffer space before base64). This made it less useful than it can be. Now it's a dynamic growing buffer. It remains allocated after use, resets to 512 when a new string starts, or leaked on exit. Resetting/deallocating the buffer right after use (at strhandle) is possible with some more code, however, it doesn't always end up used, and to cover those cases too will require even more code, so resetting only on new string is good enough for now.

STRescape holds strings in escape sequences such as OSC and DCS, and its buffer is 512 bytes. If the input is too big then trailing chars are ignored, but the test was off-by-1 such that it took 510 chars instead of 511 (before a terminating NULL is added). Now the full size can be utilized.

Previously, base64dec checked terminating input '\0' every 4 calls to base64dec_getc, where the latter progressed one or more chars on each call, and could read past '\0' in the way it was used. The input to base64dec currently comes only from OSC 52 escape seq (copy to clipboard), and reading past '\0' or even past the buffer boundary was easy to trigger. Also, even if we could trust external input to be valid base64, there are different base64 standards, and not all of them require padding to 4 bytes blocks (using trailing '=' chars). It didn't affect short OSC 52 strings because the buffer is initialized to 0's, so typically it did stop within the buffer, but if the string was trimmed to fit (the buffer is 512 bytes) then it did also read past the end of the buffer, and the decoded suffix ended up arbitrary. This patch makes base64dec_getc not progress past '\0', and instead produce fake trailing padding of '='. Additionally, at base64dec, if padding is detected at the first or second byte of a quartet, then we identify it as invalid and abort (a valid quartet has at least two leading non-padding bytes).