* Fixed bug in git helper: Do not fail if no tag could be read.

git_helper.cmake

@@ -1,5 +1,6 @@
 # Execute git command and return the output
-Function ( GitExecute COMMAND RESULT )
+Function ( GitExecute COMMAND FORCE OUT_RESULT OUT_SUCCESS )
+    Set ( ${OUT_SUCCESS} 1 PARENT_SCOPE )
     Execute_Process ( COMMAND
                         bash -c "${COMMAND}"
                       RESULT_VARIABLE
@@ -11,9 +12,13 @@ Function ( GitExecute COMMAND RESULT )
     If (    NOT ${GIT_RET} EQUAL 0
          OR NOT "${GIT_ERR}" STREQUAL ""
          OR     "${GIT_REV}" STREQUAL "" )
-        Message ( FATAL_ERROR "Unable to execute git command (command=${COMMAND} out=${GIT_REV}; err=${GIT_ERR}; ret=${GIT_RET})" )
+        If ( FORCE )
+            Message ( FATAL_ERROR "Unable to execute git command (command=${COMMAND} out=${GIT_REV}; err=${GIT_ERR}; ret=${GIT_RET})" )
+        Else ( )
+            Set ( ${OUT_SUCCESS} 0 PARENT_SCOPE )
+        EndIf ( )
     EndIf ( )
-    Set ( ${RESULT} "${GIT_REV}" PARENT_SCOPE )
+    Set ( ${OUT_RESULT} "${GIT_REV}" PARENT_SCOPE )
 EndFunction ( )
 
 # Get the version by reading the git tag
@@ -24,9 +29,20 @@ Function ( GitGetVersion GIT_ROOT OUT_MAJOR OUT_MINOR OUT_PATCH OUT_BUILD OUT_HA
     EndIf ( )
 
     # Find the latest git tag
-    GitExecute ( "git describe --tags --abbrev=1 --match v[0-9].[0-9]* HEAD" TAG )
-    GitExecute ( "git status -s -uall" DIRTY )
-    GitExecute ( "git rev-parse HEAD" HASH )
+    GitExecute ( "git describe --tags --abbrev=1 --match v[0-9].[0-9]* HEAD" False TAG SUCCESS )
+    If ( NOT ${SUCCESS} )
+        Return ( )
+    EndIf ( )
+
+    GitExecute ( "git status -s -uall" True DIRTY SUCCESS )
+    If ( NOT ${SUCCESS} )
+        Return ( )
+    EndIf ( )
+
+    GitExecute ( "git rev-parse HEAD" True HASH SUCCESS )
+    If ( NOT ${SUCCESS} )
+        Return ( )
+    EndIf ( )
 
     # Split the git revision string
     String ( REGEX REPLACE "^v" "" TAG "${TAG}" )