[master] ca45d7f21 only re-run generate.py for "developer mode" if it is present

[Nils Goroll]

commit ca45d7f2117ba76912fd4fc394c001ba94b86bd2
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Thu Dec 19 09:19:39 2019 +0100

    only re-run generate.py for "developer mode" if it is present
    
    Notice: The boolean expression does not lack parantheses, the test for
    generate.py is only to be and'ed with the test for .git
    
    Fixes #3165

diff --git a/include/Makefile.am b/include/Makefile.am
index 7899eda6e..d31231ddd 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -132,9 +132,10 @@ GENERATED_H = vcl.h $(GEN_H)
 ## except when building from a distribution
 
 vcs_version.h:
-	@if test -e $(top_srcdir)/.git || \
-	  ! test -f $(srcdir)/vmod_abi.h || \
-	  ! test -f $(srcdir)/vcs_version.h ; then \
+	@if test -e $(srcdir)/generate.py && \
+	    test -e $(top_srcdir)/.git || \
+	   ! test -f $(srcdir)/vmod_abi.h || \
+	   ! test -f $(srcdir)/vcs_version.h ; then \
 	    ${PYTHON} $(srcdir)/generate.py \
 		$(top_srcdir) $(top_builddir) ; \
 	fi