[Test] Fixed calculation of precision for string representations

This corrects the calculation of the least significant digit for all string
representations of for numbers where no decimal point was printed, e.g. "123"
and "45e+06".

site_scons/buildutils.py

@@ -247,15 +247,22 @@ def getPrecision(x):
     the number represented by the string 'x'.
     """
     x = x.lower()
+    # Patterns to consider:
+    # 123
+    # 123.45
+    # 123.45e6
+    # 123e4
+    if 'e' in x:
+        x, exponent = x.split('e')
+        exponent = int(exponent)
+    else:
+        exponent = 0
+
     decimalPt = x.find('.')
     if decimalPt == -1:
-        decimalPt = 0
+        decimalPt = len(x) - 1
 
-    if x.find('e') != -1:
-        precision = decimalPt - x.find('e') + 1
-        precision += int(x[x.find('e')+1:])
-    else:
-        precision = decimalPt - len(x) + 1
+    precision = decimalPt + exponent - len(x) + 1
 
     return 10**precision