if: Compare up to 8 components in VERSION tests

Extend the number of components tested by

  if(... VERSION_LESS ...)
  if(... VERSION_EQUAL ...)
  if(... VERSION_GREATER ...)

from 4 to 8.  The latter is a more extreme maximum.

Source/cmIfCommand.cxx

@@ -409,14 +409,18 @@ namespace
   enum Op { OpLess, OpEqual, OpGreater };
   bool HandleVersionCompare(Op op, const char* lhs_str, const char* rhs_str)
   {
-  // Parse out up to 4 components.
-  unsigned int lhs[4] = {0,0,0,0};
-  unsigned int rhs[4] = {0,0,0,0};
-  sscanf(lhs_str, "%u.%u.%u.%u", &lhs[0], &lhs[1], &lhs[2], &lhs[3]);
-  sscanf(rhs_str, "%u.%u.%u.%u", &rhs[0], &rhs[1], &rhs[2], &rhs[3]);
+  // Parse out up to 8 components.
+  unsigned int lhs[8] = {0,0,0,0,0,0,0,0};
+  unsigned int rhs[8] = {0,0,0,0,0,0,0,0};
+  sscanf(lhs_str, "%u.%u.%u.%u.%u.%u.%u.%u",
+         &lhs[0], &lhs[1], &lhs[2], &lhs[3],
+         &lhs[4], &lhs[5], &lhs[6], &lhs[7]);
+  sscanf(rhs_str, "%u.%u.%u.%u.%u.%u.%u.%u",
+         &rhs[0], &rhs[1], &rhs[2], &rhs[3],
+         &rhs[4], &rhs[5], &rhs[6], &rhs[7]);
 
   // Do component-wise comparison.
-  for(unsigned int i=0; i < 4; ++i)
+  for(unsigned int i=0; i < 8; ++i)
     {
     if(lhs[i] < rhs[i])
       {

Tests/CMakeTests/VersionTest.cmake.in

@@ -7,3 +7,10 @@ if("${CMAKE_VERSION}" VERSION_LESS "${min_ver}")
 else()
   message("CMAKE_VERSION=[${CMAKE_VERSION}] is not less than [${min_ver}]")
 endif()
+
+set(v 1.2.3.4.5.6.7)
+if("${v}.8" VERSION_LESS "${v}.9")
+  message(STATUS "${v}.8 is less than ${v}.9")
+else()
+  message(FATAL_ERROR "${v}.8 is not less than ${v}.9?")
+endif()