Latextools: Use the right exceptions to catch errors

IPython/lib/latextools.py

@@ -97,9 +97,10 b' def latex_to_png(s, encode=False, backend=None, wrap=False):'
 def latex_to_png_mpl(s, wrap):
     try:
         from matplotlib import mathtext
+        from pyparsing import ParseFatalException
     except ImportError:
         return None
-    
+
     # mpl mathtext doesn't support display math, force inline
     s = s.replace('$$', '$')
     if wrap:
@@ -110,7 +111,7 b' def latex_to_png_mpl(s, wrap):'
         f = BytesIO()
         mt.to_png(f, s, fontsize=12)
         return f.getvalue()
-    except:
+    except (ValueError, RuntimeError, ParseFatalException):
         return None
 
 
@@ -141,7 +142,7 b' def latex_to_png_dvipng(s, wrap):'
 
         with open(outfile, "rb") as f:
             return f.read()
-    except:
+    except subprocess.CalledProcessError:
         return None
     finally:
         shutil.rmtree(workdir)