Regex's in the command panel are treated as case-insensitive if there are no non-escaped letters in the pattern

/hello becomes /hello/i
/he\Slo becomes /he\Slo/i
/Hello/i becomes /Hello/i
/Hello/ becomes /Hello/

spec/extensions/command-interpreter-spec.coffee

@@ -161,6 +161,22 @@ describe "CommandInterpreter", ->
           expect(editSession.lineForScreenRow(5).fold).toBeUndefined()
           expect(editSession.lineForScreenRow(10).fold).toBeDefined()
 
+      it "is case-insentive when the pattern contains no non-escaped uppercase letters (behavior copied from vim)", ->
+        waitsForPromise ->
+          editSession.setSelectedBufferRange([[4,16], [4,20]])
+          interpreter.eval('/array', editSession)
+
+        runs ->
+          expect(editSession.getSelection().getBufferRange()).toEqual [[11,14], [11,19]]
+
+        waitsForPromise ->
+          editSession.setSelectedBufferRange([[4,16], [4,20]])
+          interpreter.eval('/a\\Sray', editSession) # You must escape the backslash, otherwise it is treated as an escaped 'S'
+
+        runs ->
+          expect(editSession.getSelection().getBufferRange()).toEqual [[11,14], [11,19]]
+
+
     describe "address range", ->
       describe "when two addresses are specified", ->
         it "selects from the begining of the left address to the end of the right address", ->

spec/extensions/command-panel-spec.coffee

@@ -241,7 +241,7 @@ describe "CommandPanel", ->
       expect(commandInterpreter.lastRelativeAddress).toBeUndefined()
       rootView.trigger 'command-panel:set-selection-as-regex-address'
       expect(commandInterpreter.lastRelativeAddress.subcommands.length).toBe 1
-      expect(commandInterpreter.lastRelativeAddress.subcommands[0].regex.toString()).toEqual "/\\(items\\)/"
+      expect(commandInterpreter.lastRelativeAddress.subcommands[0].regex.toString()).toEqual "/\\(items\\)/i"
 
   describe "when command-panel:find-in-file is triggered on an editor", ->
     it "pre-populates the command panel's editor with / and moves the cursor to the last column", ->

src/extensions/command-panel/commands/regex-address.coffee

@@ -6,9 +6,15 @@ class RegexAddress extends Address
   regex: null
   reverse: null
 
-  constructor: (pattern, isReversed) ->
+  constructor: (pattern, isReversed, options) ->
+    flags = ""
+    pattern = pattern.source if pattern.source
+
+    patternContainsCapitalLetter = /[^\\][A-Z]/.test(pattern)
+    flags += "i" unless patternContainsCapitalLetter
     @isReversed = isReversed
-    @regex = new RegExp(pattern)
+
+    @regex = new RegExp(pattern, flags)
 
   getRange: (buffer, range) ->
     rangeBefore = new Range([0, 0], range.start)