read-cache: update TEST_GIT_INDEX_VERSION support

Rename TEST_GIT_INDEX_VERSION to GIT_TEST_INDEX_VERSION for consistency with
the other GIT_TEST_ special setups and properly document its use.

Add logic in t/test-lib.sh to give a warning when the old variable is set to
let people know they need to update their environment to use the new
variable.

Signed-off-by: Ben Peart <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: benpeart

Makefile

@@ -400,7 +400,7 @@ all::
 # (defaults to "man") if you want to have a different default when
 # "git help" is called without a parameter specifying the format.
 #
-# Define TEST_GIT_INDEX_VERSION to 2, 3 or 4 to run the test suite
+# Define GIT_TEST_INDEX_VERSION to 2, 3 or 4 to run the test suite
 # with a different indexfile format version.  If it isn't set the index
 # file format used is index-v[23].
 #
@@ -2599,8 +2599,8 @@ endif
 ifdef GIT_INTEROP_MAKE_OPTS
 	@echo GIT_INTEROP_MAKE_OPTS=\''$(subst ','\'',$(subst ','\'',$(GIT_INTEROP_MAKE_OPTS)))'\' >>$@+
 endif
-ifdef TEST_GIT_INDEX_VERSION
-	@echo TEST_GIT_INDEX_VERSION=\''$(subst ','\'',$(subst ','\'',$(TEST_GIT_INDEX_VERSION)))'\' >>$@+
+ifdef GIT_TEST_INDEX_VERSION
+	@echo GIT_TEST_INDEX_VERSION=\''$(subst ','\'',$(subst ','\'',$(GIT_TEST_INDEX_VERSION)))'\' >>$@+
 endif
 	@if cmp $@+ $@ >/dev/null 2>&1; then $(RM) $@+; else mv $@+ $@; fi
 

t/README

@@ -323,6 +323,10 @@ GIT_TEST_FSMONITOR=$PWD/t7519/fsmonitor-all exercises the fsmonitor
 code path for utilizing a file system monitor to speed up detecting
 new or changed files.
 
+GIT_TEST_INDEX_VERSION=<n> exercises the index read/write code path
+for the index version specified.  Can be set to any valid version
+(currently 2, 3, or 4).
+
 Naming Tests
 ------------
 

t/test-lib.sh

@@ -134,12 +134,6 @@ export EDITOR
 GIT_TRACE_BARE=1
 export GIT_TRACE_BARE
 
-if test -n "${TEST_GIT_INDEX_VERSION:+isset}"
-then
-	GIT_INDEX_VERSION="$TEST_GIT_INDEX_VERSION"
-	export GIT_INDEX_VERSION
-fi
-
 check_var_migration () {
 	old_name=$1 new_name=$2
 	eval "old_isset=\${${old_name}:+isset}"
@@ -159,6 +153,14 @@ check_var_migration () {
 }
 
 check_var_migration GIT_FSMONITOR_TEST GIT_TEST_FSMONITOR
+check_var_migration TEST_GIT_INDEX_VERSION GIT_TEST_INDEX_VERSION
+
+# Use specific version of the index file format
+if test -n "${GIT_TEST_INDEX_VERSION:+isset}"
+then
+	GIT_INDEX_VERSION="$GIT_TEST_INDEX_VERSION"
+	export GIT_INDEX_VERSION
+fi
 
 # Add libc MALLOC and MALLOC_PERTURB test
 # only if we are not executing the test with valgrind