Make sure to not split string literals at the first character.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176447 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/Format.cpp b/lib/Format/Format.cpp
index f7702cb..2b82410 100644
--- a/lib/Format/Format.cpp
+++ b/lib/Format/Format.cpp
@@ -769,10 +769,10 @@
   StringRef::size_type
   getSplitPoint(StringRef Text, StringRef::size_type Offset) {
     StringRef::size_type SpaceOffset = Text.rfind(' ', Offset);
-    if (SpaceOffset != StringRef::npos)
+    if (SpaceOffset != StringRef::npos && SpaceOffset != 0)
       return SpaceOffset;
     StringRef::size_type SlashOffset = Text.rfind('/', Offset);
-    if (SlashOffset != StringRef::npos)
+    if (SlashOffset != StringRef::npos && SlashOffset != 0)
       return SlashOffset;
     if (Offset > 1)
       // Do not split at 0.
diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index 46eb1bc..eafc4c8 100644
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -3043,6 +3043,14 @@
   EXPECT_EQ("\"some\"\n"
             "\" text\"",
             format("\"some text\"", getLLVMStyleWithColumns(6)));
+  EXPECT_EQ("\"some\"\n"
+            "\" tex\"\n"
+            "\" and\"",
+            format("\"some tex and\"", getLLVMStyleWithColumns(6)));
+  EXPECT_EQ("\"some\"\n"
+            "\"/tex\"\n"
+            "\"/and\"",
+            format("\"some/tex/and\"", getLLVMStyleWithColumns(6)));
 
   EXPECT_EQ("variable =\n"
             "    \"long string \"\n"