[FIX] tools: find_in_path exceptions shadowing

This commit changes the default behavior of `find_in_path`: it doesn't
shallow the IOError exceptions anymore. It especially allows the asset
bundle mechanism to handle the absence of the binaries used to compile
sass/less to css.

* ir_qweb: fallback the value of `get_command` to allow QWeb to display a message like
  "Could not execute command lessc"
* ir_qweb: use of `find_in_path` to fetch binaries, allowing to look for binaries
  in `bin_path` (Windows releases)
* fixed call of `find_in_path` by `_check_external_dependencies` in
  module.py
* fixed call of `find_in_path` by report.py (it was manually raising an
IOError)

addons/report/models/report.py

@@ -49,10 +49,7 @@ from pyPdf import PdfFileWriter, PdfFileReader
 _logger = logging.getLogger(__name__)
 
 def _get_wkhtmltopdf_bin():
-    wkhtmltopdf_bin = find_in_path('wkhtmltopdf')
-    if wkhtmltopdf_bin is None:
-        raise IOError
-    return wkhtmltopdf_bin
+    return find_in_path('wkhtmltopdf')
 
 
 #--------------------------------------------------------------------------

openerp/addons/base/ir/ir_qweb.py

@@ -29,7 +29,8 @@ import openerp.tools.lru
 from openerp.http import request
 from openerp.tools.safe_eval import safe_eval as eval
 from openerp.osv import osv, orm, fields
-from openerp.tools import html_escape as escape, which
+from openerp.tools import html_escape as escape
+from openerp.tools.misc import find_in_path
 from openerp.tools.translate import _
 
 _logger = logging.getLogger(__name__)
@@ -1526,18 +1527,22 @@ class SassStylesheetAsset(PreprocessedCSS):
         return "/*! %s */\n%s" % (self.id, content)
 
     def get_command(self):
-        defpath = os.environ.get('PATH', os.defpath).split(os.pathsep)
-        sass = which('sass', path=os.pathsep.join(defpath))
+        try:
+            sass = find_in_path('sass')
+        except IOError:
+            sass = 'sass'
         return [sass, '--stdin', '-t', 'compressed', '--unix-newlines', '--compass',
                 '-r', 'bootstrap-sass']
 
 class LessStylesheetAsset(PreprocessedCSS):
     def get_command(self):
-        defpath = os.environ.get('PATH', os.defpath).split(os.pathsep)
-        if os.name == 'nt':
-            lessc = which('lessc.cmd', path=os.pathsep.join(defpath))
-        else:
-            lessc = which('lessc', path=os.pathsep.join(defpath))
+        try:
+            if os.name == 'nt':
+                lessc = find_in_path('lessc.cmd')
+            else:
+                lessc = find_in_path('lessc')
+        except IOError:
+            lessc = 'lessc'
         webpath = openerp.http.addons_manifest['web']['addons_path']
         lesspath = os.path.join(webpath, 'web', 'static', 'lib', 'bootstrap', 'less')
         return [lessc, '-', '--clean-css', '--no-js', '--no-color', '--include-path=%s' % lesspath]

openerp/addons/base/module/module.py

@@ -363,7 +363,9 @@ class module(osv.osv):
                     raise ImportError('No module named %s' % (pydep,))
 
         for binary in depends.get('bin', []):
-            if tools.find_in_path(binary) is None:
+            try:
+                tools.find_in_path(binary)
+            except IOError:
                 raise Exception('Unable to find %r in path' % (binary,))
 
     @classmethod

openerp/tools/misc.py

@@ -69,10 +69,7 @@ def find_in_path(name):
     path = os.environ.get('PATH', os.defpath).split(os.pathsep)
     if config.get('bin_path') and config['bin_path'] != 'None':
         path.append(config['bin_path'])
-    try:
-        return which(name, path=os.pathsep.join(path))
-    except IOError:
-        return None
+    return which(name, path=os.pathsep.join(path))
 
 def find_pg_tool(name):
     path = None