Ignore multiple trailing '/' in path elements (#690)

Multiple unescaped trailing path separators should be trimmed from input elements so there are no empty elements or trailing unescaped separators at the end of the path or between elements

src/internal/path/path.go

@@ -245,31 +245,30 @@ func validateEscapedElement(element string) error {
 }
 
 // trimTrailingSlash takes an escaped path element and returns an escaped path
-// element with the trailing path separator character removed if it was not
-// escaped. If there was no trailing path separator character or the separator
-// was escaped the input is returned unchanged.
+// element with the trailing path separator character(s) removed if they were not
+// escaped. If there were no trailing path separator character(s) or the separator(s)
+// were escaped the input is returned unchanged.
 func trimTrailingSlash(element string) string {
-	lastIdx := len(element) - 1
+	for len(element) > 0 && element[len(element)-1] == pathSeparator {
+		lastIdx := len(element) - 1
+		numSlashes := 0
 
-	if element[lastIdx] != pathSeparator {
-		return element
-	}
+		for i := lastIdx - 1; i >= 0; i-- {
+			if element[i] != escapeCharacter {
+				break
+			}
 
-	numSlashes := 0
+			numSlashes++
+		}
 
-	for i := lastIdx - 1; i >= 0; i-- {
-		if element[i] != escapeCharacter {
+		if numSlashes%2 != 0 {
 			break
 		}
 
-		numSlashes++
+		element = element[:lastIdx]
 	}
 
-	if numSlashes%2 != 0 {
-		return element
-	}
-
-	return element[:lastIdx]
+	return element
 }
 
 // join returns a string containing the given elements joined by the path

src/internal/path/path_test.go

@@ -169,6 +169,16 @@ var basicEscapedInputs = []testData{
 		},
 		expectedString: `this/is/a/path`,
 	},
+	{
+		name: "MultipleTrailingElementSeparator",
+		input: []string{
+			`this`,
+			`is`,
+			`a///`,
+			`path`,
+		},
+		expectedString: `this/is/a/path`,
+	},
 	{
 		name: "TrailingSeparatorAtEnd",
 		input: []string{
@@ -179,6 +189,16 @@ var basicEscapedInputs = []testData{
 		},
 		expectedString: `this/is/a/path`,
 	},
+	{
+		name: "MultipleTrailingSeparatorAtEnd",
+		input: []string{
+			`this`,
+			`is`,
+			`a`,
+			`path///`,
+		},
+		expectedString: `this/is/a/path`,
+	},
 	{
 		name: "TrailingSeparatorWithEmptyElementAtEnd",
 		input: []string{