Index: docs/ClangFormatStyleOptions.rst
===================================================================
--- docs/ClangFormatStyleOptions.rst
+++ docs/ClangFormatStyleOptions.rst
@@ -1363,6 +1363,35 @@
        #endif
 
 
+ **IndentReference** (``IndentReferenceStyle``)
+   Indent relative to the previous line or in absolute.
+
+   Only useful for when formatting only certain lines.
+
+   Possible values:
+
+   * ``IRS_Relative`` (in configuration: ``Relative``)
+     Indent relative to previous line, e.g.:
+
+     .. code-block:: c
+
+       int a = 0;
+        int f(void) {
+          int i = 0;
+          return i;
+       }
+
+   * ``IRS_Absolute`` (in configuration: ``Absolute``)
+     Indent as if the whole file was formatted, e.g.:
+
+     .. code-block:: c
+
+       int a = 0;
+        int f(void) {
+         int i = 0;
+         return i;
+       }
+
 
 **IndentWidth** (``unsigned``)
   The number of columns to use for indentation.
Index: include/clang/Format/Format.h
===================================================================
--- include/clang/Format/Format.h
+++ include/clang/Format/Format.h
@@ -1094,6 +1094,30 @@
   /// The preprocessor directive indenting style to use.
   PPDirectiveIndentStyle IndentPPDirectives;
 
+  /// Different styles for indenting, used for partial formatting.
+  enum IndentReferenceStyle {
+    /// Indent relative to previous line, e.g.:
+    /// \code
+    ///   int a = 0;
+    ///    int f(void) { // mis-indented by one space
+    ///      int i = 0; <- those lines indented relative to
+    ///      return i;  <- the indentation of f(), including
+    ///    }            <- the one space mis-indentation
+    /// \endcode
+    IRS_Relative,
+    /// Indent as if the whole file was formatted, e.g.:
+    /// \code
+    ///   int a = 0;
+    ///    int f(void) { // mis-indented by one space
+    ///     int i = 0; <- those lines indented absolutely;
+    ///     return i;  <- i.e. ignoring f()'s one space
+    ///   }            <- mis-indentation
+    /// \endcode
+    IRS_Absolute,
+  };
+
+  IndentReferenceStyle IndentReference;
+
   /// The number of columns to use for indentation.
   /// \code
   ///    IndentWidth: 3
@@ -1722,6 +1746,7 @@
            IncludeStyle.IncludeCategories == R.IncludeStyle.IncludeCategories &&
            IndentCaseLabels == R.IndentCaseLabels &&
            IndentPPDirectives == R.IndentPPDirectives &&
+           IndentReference == R.IndentReference &&
            IndentWidth == R.IndentWidth && Language == R.Language &&
            IndentWrappedFunctionNames == R.IndentWrappedFunctionNames &&
            JavaScriptQuotes == R.JavaScriptQuotes &&
Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -241,6 +241,13 @@
   }
 };
 
+template <> struct ScalarEnumerationTraits<FormatStyle::IndentReferenceStyle> {
+  static void enumeration(IO &IO, FormatStyle::IndentReferenceStyle &Value) {
+    IO.enumCase(Value, "Relative", FormatStyle::IRS_Relative);
+    IO.enumCase(Value, "Absolute", FormatStyle::IRS_Absolute);
+  }
+};
+
 template <> struct ScalarEnumerationTraits<FormatStyle::PointerAlignmentStyle> {
   static void enumeration(IO &IO, FormatStyle::PointerAlignmentStyle &Value) {
     IO.enumCase(Value, "Middle", FormatStyle::PAS_Middle);
@@ -411,6 +418,7 @@
     IO.mapOptional("IncludeIsMainRegex", Style.IncludeStyle.IncludeIsMainRegex);
     IO.mapOptional("IndentCaseLabels", Style.IndentCaseLabels);
     IO.mapOptional("IndentPPDirectives", Style.IndentPPDirectives);
+    IO.mapOptional("IndentReference", Style.IndentReference);
     IO.mapOptional("IndentWidth", Style.IndentWidth);
     IO.mapOptional("IndentWrappedFunctionNames",
                    Style.IndentWrappedFunctionNames);
@@ -670,6 +678,7 @@
   LLVMStyle.IncludeStyle.IncludeBlocks = tooling::IncludeStyle::IBS_Preserve;
   LLVMStyle.IndentCaseLabels = false;
   LLVMStyle.IndentPPDirectives = FormatStyle::PPDIS_None;
+  LLVMStyle.IndentReference = FormatStyle::IRS_Relative;
   LLVMStyle.IndentWrappedFunctionNames = false;
   LLVMStyle.IndentWidth = 2;
   LLVMStyle.JavaScriptQuotes = FormatStyle::JSQS_Leave;
Index: lib/Format/UnwrappedLineFormatter.cpp
===================================================================
--- lib/Format/UnwrappedLineFormatter.cpp
+++ lib/Format/UnwrappedLineFormatter.cpp
@@ -1089,10 +1089,13 @@
             format(Tok->Children, DryRun);
 
       // Adapt following lines on the current indent level to the same level
-      // unless the current \c AnnotatedLine is not at the beginning of a line.
+      // if indentation should be relative and unless the
+      // current \c AnnotatedLine is not at the beginning of a line.
+      bool RelativeIndentation =
+          Style.IndentReference != FormatStyle::IRS_Absolute;
       bool StartsNewLine =
           TheLine.First->NewlinesBefore > 0 || TheLine.First->IsFirst;
-      if (StartsNewLine)
+      if (RelativeIndentation && StartsNewLine)
         IndentTracker.adjustToUnmodifiedLine(TheLine);
       if (!DryRun) {
         bool ReformatLeadingWhitespace =
Index: test/Format/line-ranges-indent-abs.c
===================================================================
--- /dev/null
+++ test/Format/line-ranges-indent-abs.c
@@ -0,0 +1,10 @@
+// RUN: grep -Ev "// *[A-Z-]+:" %s \
+// RUN:   | clang-format -style="{BasedOnStyle: LLVM, IndentReference: Absolute}" -lines=2:2 \
+// RUN:   | FileCheck -strict-whitespace %s
+// CHECK: {{^\ int f\(void\) \{$}}
+ int f(void) {
+// CHECK: {{^\ \ int i = 0;$}}
+  int i = 0;
+// CHECK: {{^\ \ return i;$}}
+  return i;
+}
Index: test/Format/line-ranges-indent-abs.m
===================================================================
--- /dev/null
+++ test/Format/line-ranges-indent-abs.m
@@ -0,0 +1,9 @@
+// RUN: grep -Ev "// *[A-Z-]+:" %s \
+// RUN:   | clang-format -style="{BasedOnStyle: LLVM, IndentReference: Absolute}" -lines=2:2 \
+// RUN:   | FileCheck -strict-whitespace %s
+// CHECK: {{^\ \@protocol\ A$}}
+ @protocol A
+// CHECK: {{^-\ \(void\)f;$}}
+- (void)f;
+// CHECK: {{^\@end$}}
+@end
Index: test/Format/line-ranges-indent-rel.c
===================================================================
--- /dev/null
+++ test/Format/line-ranges-indent-rel.c
@@ -0,0 +1,10 @@
+// RUN: grep -Ev "// *[A-Z-]+:" %s \
+// RUN:   | clang-format -style=LLVM -lines=2:2 \
+// RUN:   | FileCheck -strict-whitespace %s
+// CHECK: {{^\ int f\(void\) \{$}}
+ int f(void) {
+// CHECK: {{^\ \ \ int i = 0;$}}
+  int i = 0;
+// CHECK: {{^\ \ \ return i;$}}
+  return i;
+}