If you have one file that you want updated in several places in the depot, you have a few options.
...and then propagate changes to the various branches using the following commands:
p4 integ //depot/sharedfiles/COPYRIGHT.TXT //depot/r1.0/COPYRIGHT.TXT
p4 integ //depot/sharedfiles/COPYRIGHT.TXT //depot/r1.2/COPYRIGHT.TXT
p4 integ //depot/sharedfiles/COPYRIGHT.TXT //depot/r2.0/COPYRIGHT.TXT
The process above can be scripted. See Submitting Files Non-interactively for more information on scripting submit operations.
and then only work on one at a time. In this case, the client spec "View" you use for the /r
codeline appears as follows:
Reorganize your code to avoid this construct. Often, a build system can be reworked slightly to accomplish this.
For more information on Codelines and Branching see Chapter 6 of the Perforce User's Guide.