I can confirm this issue. Only the first word on each page is printed on any written book which I try to read from a version before the affected snapshots, in both singleplayer and multiplayer. Unsigned book & quill items with text in them do not seem to be affected by this bug, in singleplayer at least.
I have run tests using a backup of my world save from 1.8. By loading the world file in older snapshots, I have determined that this bug is apparently a lot older than anyone realized - it first appears, in fact, in 15w33c, as can be seen here: http://imgur.com/a/W05D1
I can confirm this issue, it's been happening to my creative multiplayer server since I updated to 16w02a. Reverting to 15w51b does not fix the issue. Logs can be found at the links below:
http://pastebin.com/82BGTgYG
http://pastebin.com/Lrd2w3fC
Oddly, the bottom one (the crash report) cites the source block type of the block being updated as ID #151 (the daylight detector), but cites the block itself as being "minecraft:beacon". Might this have something to do with the issue?
This bug is still an issue in 15w47a. It happens to me no matter which way I go, and commands (such as /kill or /tp) don't take effect for a long while, even when inputting the commands into the server console.
Although this has not happened to me before this version, I can confirm that this bug is still present in 13w41b. Reloading didn't seem to help either; the server was restarted multiple times during the storm and still the rain persisted.
@ Markku - If you look at block IDs, there are two types of water blocks - "flowing" and "static". If you use the /give command to get and place them both, you'll notice that the "flowing" water behaves like water placed from a bucket, while the "static" water acts like the issue case seen here - not flowing until it receives an update. This leaves me to conclude that melting ice replaces itself with the incorrect block.
I can understand why ice may have melted into static water in the past, since all naturally-generated bodies of water were static and any tampering with them would cause them to be forever flowing, but didn't they fix water source mechanics in 1.5?
I've been thinking, couldn't this issue in particular be fixed simply by telling the code to place Block ID 8 (flowing water) instead of Block ID 9 (static water) when ice is melted by light?
This deals with water appearing when suspended. Whether or not it flows is not the focus here... Do you still feel that my issue is to be lumped with this one anyway?
Confirmed in 1.16.3, and have been observing this bug for years across many different game versions. I've had various sources of this "phantom light" appearing in a completely sealed underground room. Most I was able to fill up with blocks, but one source won't go away even when I completely fill in the space it's occupying. Sometimes, the light seems to be emanating from a solid block, and will only go away if I break that block.