The standard states:
"GL_INVALID_OPERATION is generated if glLight is executed between the execution of glBegin and the corresponding execution of glEnd.", but invocation of the interface glLighti between glBegin and glEnd does not generate GL_INVALID_OPERATION error.
*** Bug 17410 has been marked as a duplicate of this bug. ***
Fix pushed to master (418b6035133e4e10bdc46fe39af192afd087dd69) and mesa_7_2_branch.