* lisp/progmodes/ruby-mode.el (ruby-syntax-propertize-function):

Backtrack one char if the global/char-literal var matcher hits
inside a string.  The next char could be the beginning of an
expression expansion.

* test/automated/ruby-mode-tests.el
(ruby-interpolation-after-dollar-sign): New test.

4 files changed, 20 insertions, 3 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 3bbacb85e97..7c838a61fe5 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2014-05-05  Dmitry Gutov  <dgutov@yandex.ru>
+
+        * progmodes/ruby-mode.el (ruby-syntax-propertize-function):
+        Backtrack one char if the global/char-literal var matcher hits
+        inside a string.  The next char could be the beginning of an
+        expression expansion.
+
 2014-05-05  Glenn Morris  <rgm@gnu.org>
 
         * help-fns.el (describe-function-1): Test for an autoload before a
diff --git a/lisp/progmodes/ruby-mode.el b/lisp/progmodes/ruby-mode.el
index 912736707ef..74edf7a680f 100644
--- a/lisp/progmodes/ruby-mode.el
+++ b/lisp/progmodes/ruby-mode.el
@@ -1804,9 +1804,10 @@ It will be properly highlighted even when the call omits parens.")
       ;; $' $" $` .... are variables.
       ;; ?' ?" ?` are character literals (one-char strings in 1.9+).
       ("\\([?$]\\)[#\"'`]"
-       (1 (unless (save-excursion
-                    ;; Not within a string.
-                    (nth 3 (syntax-ppss (match-beginning 0))))
+       (1 (if (save-excursion
+                (nth 3 (syntax-ppss (match-beginning 0))))
+              ;; Within a string, skip.
+              (goto-char (match-end 1))
             (string-to-syntax "\\"))))
       ;; Part of symbol when at the end of a method name.
       ("[!?]"
diff --git a/test/ChangeLog b/test/ChangeLog
index a02b8e80395..0a3e89e7385 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,8 @@
+2014-05-05  Dmitry Gutov  <dgutov@yandex.ru>
+
+        * automated/ruby-mode-tests.el
+        (ruby-interpolation-after-dollar-sign): New test.
+
 2014-05-05  Glenn Morris  <rgm@gnu.org>
 
         * automated/help-fns.el: New file.
diff --git a/test/automated/ruby-mode-tests.el b/test/automated/ruby-mode-tests.el
index f6fddb5ef4c..0ad5650cd77 100644
--- a/test/automated/ruby-mode-tests.el
+++ b/test/automated/ruby-mode-tests.el
@@ -452,6 +452,10 @@ VALUES-PLIST is a list with alternating index and value elements."
   (ruby-assert-face "%w{foo #@bar}" 8 font-lock-string-face)
   (ruby-assert-face "%s{foo #@bar}" 8 font-lock-string-face))
 
+(ert-deftest ruby-interpolation-after-dollar-sign ()
+  (ruby-assert-face "\"$#{balance}\"" 2 'font-lock-string-face)
+  (ruby-assert-face "\"$#{balance}\"" 3 'font-lock-variable-name-face))
+
 (ert-deftest ruby-no-unknown-percent-literals ()
   ;; No folding of case.
   (ruby-assert-face "%S{foo}" 4 nil)