Debugger: Make Python's subprocess dependency optional

This is only used to display array data using gnuplot.

Task-Number: QTCREATORBUG-10205
Change-Id: I9a9173860e4f6d37f475c7f101c0e85d104ab10a
Reviewed-by: hjk <hjk121@nokiamail.com>

share/qtcreator/dumper/dumper.py

@@ -83,10 +83,15 @@ def hasPlot():
     fileName = "/usr/bin/gnuplot"
     return os.path.isfile(fileName) and os.access(fileName, os.X_OK)
 
-def arrayForms():
-    if hasPlot():
-        return "Normal,Plot"
-    return "Normal"
+try:
+    import subprocess
+    def arrayForms():
+        if hasPlot():
+            return "Normal,Plot"
+        return "Normal"
+except:
+    def arrayForms():
+        return "Normal"
 
 
 def bytesToString(b):

share/qtcreator/dumper/gbridge.py

@@ -12,7 +12,6 @@ except:
 import inspect
 import os
 import os.path
-import subprocess
 import sys
 import tempfile
 import traceback
@@ -1530,6 +1529,7 @@ class Dumper(DumperBase):
                     stdin=subprocess.PIPE)
             gnuplotPid[iname] = gnuplotPipe[iname].pid
         f = gnuplotPipe[iname].stdin;
+        # On Ubuntu install gnuplot-x11
         f.write("set term wxt noraise\n")
         f.write("set title 'Data fields'\n")
         f.write("set xlabel 'Index'\n")