Decompressors should check for "." in extension

Fixes hashicorp/terraform#11438

Decompressors were suffix checking only for the extension WITHOUT a
period. This was causing directories and files ending with that to be
treated as an archive incorrectly.

Author: mitchellh

client.go

@@ -153,7 +153,7 @@ func (c *Client) Get() error {
 		// We don't appear to... but is it part of the filename?
 		matchingLen := 0
 		for k, _ := range decompressors {
-			if strings.HasSuffix(u.Path, k) && len(k) > matchingLen {
+			if strings.HasSuffix(u.Path, "."+k) && len(k) > matchingLen {
 				archiveV = k
 				matchingLen = len(k)
 			}

get_test.go

@@ -31,6 +31,21 @@ func TestGet_file(t *testing.T) {
 	}
 }
 
+// https://github.com/hashicorp/terraform/issues/11438
+func TestGet_fileDecompressorExt(t *testing.T) {
+	dst := tempDir(t)
+	u := testModule("basic-tgz")
+
+	if err := Get(dst, u); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	mainPath := filepath.Join(dst, "main.tf")
+	if _, err := os.Stat(mainPath); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+}
+
 // https://github.com/hashicorp/terraform/issues/8418
 func TestGet_filePercent2F(t *testing.T) {
 	dst := tempDir(t)

test-fixtures/basic-tgz/main.tf

@@ -0,0 +1 @@
+# Hello