diff --git a/headless-services/commons/commons-util/src/main/java/org/springframework/ide/vscode/commons/util/text/DocumentRegion.java b/headless-services/commons/commons-util/src/main/java/org/springframework/ide/vscode/commons/util/text/DocumentRegion.java
index 596f2ffaa..7e88d495a 100644
--- a/headless-services/commons/commons-util/src/main/java/org/springframework/ide/vscode/commons/util/text/DocumentRegion.java
+++ b/headless-services/commons/commons-util/src/main/java/org/springframework/ide/vscode/commons/util/text/DocumentRegion.java
@@ -125,6 +125,19 @@ public class DocumentRegion implements CharSequence, IRegion {
 			throw new IndexOutOfBoundsException(""+offset);
 		}
 	}
+	
+	/**
+	 * Like charAt, but doesn't IndexOutOfBoundsException. Instead it
+	 * return (char)0.
+	 */
+	public char safeCharAt(int offset) {
+		try {
+			return charAt(offset);
+		} catch (IndexOutOfBoundsException e) {
+			return 0;
+		}
+	}
+
 
 	/**
 	 * Determines whether this range contains a given (absolute) offset.
diff --git a/headless-services/concourse-language-server/src/main/java/org/springframework/ide/vscode/concourse/github/GithubValueParsers.java b/headless-services/concourse-language-server/src/main/java/org/springframework/ide/vscode/concourse/github/GithubValueParsers.java
index 6559393bd..8fa2783f5 100644
--- a/headless-services/concourse-language-server/src/main/java/org/springframework/ide/vscode/concourse/github/GithubValueParsers.java
+++ b/headless-services/concourse-language-server/src/main/java/org/springframework/ide/vscode/concourse/github/GithubValueParsers.java
@@ -89,7 +89,7 @@ public class GithubValueParsers {
 				for (String expectedPrefix : GithubRepoContentAssistant.URI_PREFIXES) {
 					int lastChar = expectedPrefix.length()-1;
 					if (str.startsWith(expectedPrefix.substring(0, lastChar))) {
-						char actualSeparator = str.charAt(lastChar);
+						char actualSeparator = str.safeCharAt(lastChar);
 						char expectedSeparator = expectedPrefix.charAt(lastChar);
 						if (actualSeparator==expectedSeparator) {
 							return expectedPrefix;