pgsql: Fix PL/Python traceback for error in separate file

Fix PL/Python traceback for error in separate file

It assumed that the lineno from the traceback always refers to the
PL/Python function. If you created a PL/Python function that imports
some code, runs it, and that code raises an exception, PLy_traceback
would get utterly confused.

Now we look at the file name reported with the traceback and only
print the source line if it came from the PL/Python function.

Jan Urbański

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/395fcac29906d22615ba68bd1dfa31daf691979e

Modified Files
--------------
src/pl/plpython/plpython.c | 24 ++++++++++++++++++++++--
1 files changed, 22 insertions(+), 2 deletions(-)