Is there a rule somewhere for this?
For example, a Cleric cast True Seeing on a Barbarian and then this Barbarian dies. If the Cleric Raise Dead him, will the Barbarian still have True Seeing?
The Rules seem silent on this question:
Duration
A spell's duration entry tells you how long the magical energy of the spell lasts.
Timed Durations
Many durations are measured in rounds, minutes, hours, or other increments. When the time is up, the magic goes away and the spell ends.
Subjects, Effects, and Areas
If the spell affects creatures directly, the result travels with the subjects for the spell's duration. If the spell creates an effect, the effect lasts for the duration. The effect might move or remain still. Such an effect can be destroyed prior to when its duration ends. If the spell affects an area, then the spell stays with that area for its duration.
and
Dead
The character's hit points are reduced to a negative amount equal to his Constitution score, his Constitution drops to 0, or he is killed outright by a spell or effect. The character's soul leaves his body. Dead characters cannot benefit from normal or magical healing, but they can be restored to life via magic. A dead body decays normally unless magically preserved, but magic that restores a dead character to life also restores the body either to full health or to its condition at the time of death (depending on the spell or device). Either way, resurrected characters need not worry about rigor mortis, decomposition, and other conditions that affect dead bodies.
So a spell lasts for it's full duration. Period. Nothing else says that the spell ends when the caster or the subject dies. Not even the description of "Dead" says that your spells end.
Since the default is that the spell lasts the full duration and no specific text says it ends when you die, therefore it doesn't end with death.