Update python's linecache when a python file is written

This fixes an annoying bug where your ability to set breakpoints would
be based entirely on whether or not there was an executable line at the
place you want the breakpoint when you first opened the file for
editing.

Author: mvanderkamp

plugin/pudb.vim

@@ -219,6 +219,18 @@ function! s:LocationList()
 endfunction
 
 
+"
+" Clear the python line cache for the given file if it has changed
+"
+function! s:ClearLineCache(filename)
+pythonx << EOF
+import linecache
+import vim
+linecache.checkcache(vim.eval('a:filename'))
+EOF
+endfunction
+
+
 " Define ex commands for all the above functions so they are user-accessible.
 command! PudbClearAll call s:ClearAll()
 command! PudbEdit     call s:Edit()
@@ -237,7 +249,11 @@ if &filetype == 'python'
 endif
 
 
-" Also update when the file is first read.
 augroup pudb
+    " Also update when the file is first read.
     autocmd BufReadPost *.py call s:Update()
+
+    " Force a linecache update after writes so the breakpoints can be parsed
+    " correctly.
+    autocmd BufWritePost *.py call s:ClearLineCache(expand('%:p'))
 augroup end