master 0a7152e: Fix up previous replace-in-string commit

[Lars Ingebrigtsen]

branch: master
commit 0a7152e095e51febedf3da794eacb3a6b538e64e
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Fix up previous replace-in-string commit
    
    * lisp/subr.el (replace-in-string): Fix thinko in implementation.
---
 lisp/subr.el            | 6 +++++-
 test/lisp/subr-tests.el | 8 +++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/lisp/subr.el b/lisp/subr.el
index b833176..f3c1e20 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -4430,7 +4430,11 @@ This function returns a freshly created string."
                             (aref fromstring if)))
               (setq ii (1+ ii)
                     if (1+ if)))
-            (when (= if (length fromstring))
+            (if (not (= if (length fromstring)))
+                ;; We didn't have a match after all.
+                (setq i (1+ i))
+              ;; We had one, so gather the previous part and the
+              ;; substition.
               (when (not (= start i))
                 (push (substring instring start i) result))
               (push tostring result)
diff --git a/test/lisp/subr-tests.el b/test/lisp/subr-tests.el
index 8bec097..2adb4a6 100644
--- a/test/lisp/subr-tests.el
+++ b/test/lisp/subr-tests.el
@@ -450,7 +450,13 @@ See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=19350.";
   (should (equal (replace-in-string "zot" "bar" "barfoozot")
                  "barfoobar"))
   (should (equal (replace-in-string "z" "bar" "barfoozot")
-                 "barfoobarot")))
+                 "barfoobarot"))
+  (should (equal (replace-in-string "zot" "bar" "zat")
+                 "zat"))
+  (should (equal (replace-in-string "azot" "bar" "zat")
+                 "zat"))
+  (should (equal (replace-in-string "azot" "bar" "azot")
+                 "bar")))
 
 (provide 'subr-tests)
 ;;; subr-tests.el ends here