1 files changed, 34 insertions, 0 deletions

diff --git a/vendor/github.com/hashicorp/terraform/config/module/versions.go b/vendor/github.com/hashicorp/terraform/config/module/versions.go
index 8348d4b..29701b9 100644
--- a/vendor/github.com/hashicorp/terraform/config/module/versions.go
+++ b/vendor/github.com/hashicorp/terraform/config/module/versions.go
@@ -3,7 +3,9 @@ package module
 import (
         "errors"
         "fmt"
+        "regexp"
         "sort"
+        "strings"
 
         version "github.com/hashicorp/go-version"
         "github.com/hashicorp/terraform/registry/response"
@@ -11,6 +13,8 @@ import (
 
 const anyVersion = ">=0.0.0"
 
+var explicitEqualityConstraint = regexp.MustCompile("^=[0-9]")
+
 // return the newest version that satisfies the provided constraint
 func newest(versions []string, constraint string) (string, error) {
         if constraint == "" {
@@ -21,6 +25,30 @@ func newest(versions []string, constraint string) (string, error) {
                 return "", err
         }
 
+        // Find any build metadata in the constraints, and
+        // store whether the constraint is an explicit equality that
+        // contains a build metadata requirement, so we can return a specific,
+        // if requested, build metadata version
+        var constraintMetas []string
+        var equalsConstraint bool
+        for i := range cs {
+                constraintMeta := strings.SplitAfterN(cs[i].String(), "+", 2)
+                if len(constraintMeta) > 1 {
+                        constraintMetas = append(constraintMetas, constraintMeta[1])
+                }
+        }
+
+        if len(cs) == 1 {
+                equalsConstraint = explicitEqualityConstraint.MatchString(cs.String())
+        }
+
+        // If the version string includes metadata, this is valid in go-version,
+        // However, it's confusing as to what expected behavior should be,
+        // so give an error so the user can do something more logical
+        if (len(cs) > 1 || !equalsConstraint) && len(constraintMetas) > 0 {
+                return "", fmt.Errorf("Constraints including build metadata must have explicit equality, or are otherwise too ambiguous: %s", cs.String())
+        }
+
         switch len(versions) {
         case 0:
                 return "", errors.New("no versions found")
@@ -58,6 +86,12 @@ func newest(versions []string, constraint string) (string, error) {
                         continue
                 }
                 if cs.Check(v) {
+                        // Constraint has metadata and is explicit equality
+                        if equalsConstraint && len(constraintMetas) > 0 {
+                                if constraintMetas[0] != v.Metadata() {
+                                        continue
+                                }
+                        }
                         return versions[i], nil
                 }
         }