Made the git version retrieval more reliable

CMakeLists.txt

@@ -13,10 +13,18 @@ set(CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake/)
 include(OpenMWMacros)
 
 # Version
+set(OPENMW_VERSION_MAJOR 0)
+set(OPENMW_VERSION_MINOR 29)
+set(OPENMW_VERSION_RELEASE 0)
 
-include(GetGitRevisionDescription)
+set(OPENMW_VERSION "${OPENMW_VERSION_MAJOR}.${OPENMW_VERSION_MINOR}.${OPENMW_VERSION_RELEASE}")
 
-get_git_tag_revision(TAGHASH --tags --max-count=1 "HEAD...")
+if(EXISTS ${PROJECT_SOURCE_DIR}/.git)
+    find_package(Git)
+
+    if(GIT_FOUND)
+        include(GetGitRevisionDescription)
+        get_git_tag_revision(TAGHASH --tags --max-count=1)
         get_git_head_revision(REFSPEC COMMITHASH)
         git_describe(VERSION --tags ${TAGHASH})
 
@@ -32,8 +40,12 @@ if (MATCH)
 
             message(STATUS "Configuring OpenMW ${OPENMW_VERSION}...")
         else(MATCH)
-    message(FATAL_ERROR "Failed to get valid version information from Git")
+            message(WARNING "Failed to get valid version information from Git")
         endif(MATCH)
+    else(GIT_FOUND)
+        message(WARNING "Git executable not found")
+    endif(GIT_FOUND)
+endif(EXISTS ${PROJECT_SOURCE_DIR}/.git)
 
 # doxygen main page
 

cmake/GetGitRevisionDescription.cmake

@@ -85,10 +85,6 @@ function(get_git_head_revision _refspecvar _hashvar)
 endfunction()
 
 function(git_describe _var)
-    if(NOT GIT_FOUND)
-        find_package(Git QUIET)
-    endif()
-
     #get_git_head_revision(refspec hash)
 
     if(NOT GIT_FOUND)
@@ -124,6 +120,20 @@ function(git_describe _var)
                     out
                     OUTPUT_STRIP_TRAILING_WHITESPACE)
 
+    if(NOT res EQUAL 0)
+        execute_process(COMMAND
+                        "${GIT_EXECUTABLE}"
+                        describe
+                        "--always"
+                        WORKING_DIRECTORY
+                        "${CMAKE_SOURCE_DIR}"
+                        RESULT_VARIABLE
+                        res
+                        OUTPUT_VARIABLE
+                        out
+                        OUTPUT_STRIP_TRAILING_WHITESPACE)
+    endif()
+
     if(NOT res EQUAL 0)
         set(out "${out}-${res}-NOTFOUND")
     endif()
@@ -133,7 +143,8 @@ endfunction()
 
 function(get_git_tag_revision _var)
     if(NOT GIT_FOUND)
-        find_package(Git QUIET)
+        set(${_var} "GIT-NOTFOUND" PARENT_SCOPE)
+        return()
     endif()
 
     execute_process(COMMAND