git tests: skip tests on case-only rename commit for old Gits

In Git prior to 1.8.2 `git reset` used to return exit code 1,
even if completes successfully. It affects only rare cases,
so it was decided not to fix it: IDEA-182150

plugins/git4idea/tests/git4idea/tests/GitCommitTest.kt

@@ -22,7 +22,9 @@ import com.intellij.openapi.vcs.changes.Change
 import com.intellij.util.containers.ContainerUtil
 import git4idea.GitUtil
 import git4idea.checkin.GitCheckinEnvironment
+import git4idea.config.GitVersion
 import git4idea.test.*
+import org.junit.Assume.assumeTrue
 import java.io.File
 import java.util.*
 
@@ -133,6 +135,8 @@ class GitCommitTest : GitSingleRepoTest() {
   }
 
   fun `test commit case rename & don't commit one staged file`() {
+    `assume version where git reset returns 0 exit code on success `()
+
     tac("s.java")
     generateCaseRename("a.java", "A.java")
     echo("s.java", "staged")
@@ -157,6 +161,8 @@ class GitCommitTest : GitSingleRepoTest() {
   }
 
   fun `test commit case rename & don't commit one staged simple rename, then rename should remain staged`() {
+    `assume version where git reset returns 0 exit code on success `()
+
     echo("before.txt", "some\ncontent\nere")
     addCommit("created before.txt")
     generateCaseRename("a.java", "A.java")
@@ -181,6 +187,8 @@ class GitCommitTest : GitSingleRepoTest() {
   }
 
   fun `test commit case rename + one unstaged file & don't commit one staged file`() {
+    `assume version where git reset returns 0 exit code on success `()
+
     tac("s.java")
     tac("m.java")
     generateCaseRename("a.java", "A.java")
@@ -209,6 +217,8 @@ class GitCommitTest : GitSingleRepoTest() {
   }
 
   fun `test commit case rename & don't commit a file which is both staged and unstaged, should reset and restore`() {
+    `assume version where git reset returns 0 exit code on success `()
+
     tac("c.java")
     generateCaseRename("a.java", "A.java")
     echo("c.java", "staged")
@@ -267,6 +277,11 @@ class GitCommitTest : GitSingleRepoTest() {
     assertEquals(initialContent + additionalContent, git("show HEAD:A.java"))
   }
 
+  private fun `assume version where git reset returns 0 exit code on success `() {
+    assumeTrue("Not testing: git reset returns 1 and fails the commit process in ${vcs.version}",
+               vcs.version.isLaterOrEqual(GitVersion(1, 8, 2, 0)))
+  }
+
   private fun generateCaseRename(from: String, to: String) {
     tac(from)
     git("mv -f $from $to")