From ca9abe98a9a6e0c34f906941674b2cfa9cd6ca0c Mon Sep 17 00:00:00 2001
From: Marshall Greenblatt <magreenblatt@gmail.com>
Date: Fri, 5 May 2017 15:34:20 -0400
Subject: [PATCH] Fix DCHECK during Find (issue #2050)

---
 include/capi/cef_browser_capi.h     | 15 +++++++++------
 include/cef_browser.h               | 15 +++++++++------
 libcef/browser/browser_host_impl.cc |  8 ++++++++
 libcef/browser/browser_host_impl.h  |  3 +++
 4 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/include/capi/cef_browser_capi.h b/include/capi/cef_browser_capi.h
index 9e1362f6c..9485dd534 100644
--- a/include/capi/cef_browser_capi.h
+++ b/include/capi/cef_browser_capi.h
@@ -430,12 +430,15 @@ typedef struct _cef_browser_host_t {
       struct _cef_pdf_print_callback_t* callback);
 
   ///
-  // Search for |searchText|. |identifier| can be used to have multiple searches
-  // running simultaniously. |forward| indicates whether to search forward or
-  // backward within the page. |matchCase| indicates whether the search should
-  // be case-sensitive. |findNext| indicates whether this is the first request
-  // or a follow-up. The cef_find_handler_t instance, if any, returned via
-  // cef_client_t::GetFindHandler will be called to report find results.
+  // Search for |searchText|. |identifier| must be a unique ID and these IDs
+  // must strictly increase so that newer requests always have greater IDs than
+  // older requests. If |identifier| is zero or less than the previous ID value
+  // then it will be automatically assigned a new valid ID. |forward| indicates
+  // whether to search forward or backward within the page. |matchCase|
+  // indicates whether the search should be case-sensitive. |findNext| indicates
+  // whether this is the first request or a follow-up. The cef_find_handler_t
+  // instance, if any, returned via cef_client_t::GetFindHandler will be called
+  // to report find results.
   ///
   void (CEF_CALLBACK *find)(struct _cef_browser_host_t* self, int identifier,
       const cef_string_t* searchText, int forward, int matchCase,
diff --git a/include/cef_browser.h b/include/cef_browser.h
index 3b4ed1617..f12facb9a 100644
--- a/include/cef_browser.h
+++ b/include/cef_browser.h
@@ -472,12 +472,15 @@ class CefBrowserHost : public virtual CefBaseRefCounted {
                           CefRefPtr<CefPdfPrintCallback> callback) =0;
 
   ///
-  // Search for |searchText|. |identifier| can be used to have multiple searches
-  // running simultaniously. |forward| indicates whether to search forward or
-  // backward within the page. |matchCase| indicates whether the search should
-  // be case-sensitive. |findNext| indicates whether this is the first request
-  // or a follow-up. The CefFindHandler instance, if any, returned via
-  // CefClient::GetFindHandler will be called to report find results.
+  // Search for |searchText|. |identifier| must be a unique ID and these IDs
+  // must strictly increase so that newer requests always have greater IDs than
+  // older requests. If |identifier| is zero or less than the previous ID value
+  // then it will be automatically assigned a new valid ID. |forward| indicates
+  // whether to search forward or backward within the page. |matchCase|
+  // indicates whether the search should be case-sensitive. |findNext| indicates
+  // whether this is the first request or a follow-up. The CefFindHandler
+  // instance, if any, returned via CefClient::GetFindHandler will be called to
+  // report find results.
   ///
   /*--cef()--*/
   virtual void Find(int identifier, const CefString& searchText,
diff --git a/libcef/browser/browser_host_impl.cc b/libcef/browser/browser_host_impl.cc
index 14df2b671..096ec108a 100644
--- a/libcef/browser/browser_host_impl.cc
+++ b/libcef/browser/browser_host_impl.cc
@@ -784,6 +784,14 @@ void CefBrowserHostImpl::Find(int identifier, const CefString& searchText,
     if (!web_contents_)
       return;
 
+    // Every find request must have a unique ID and these IDs must strictly
+    // increase so that newer requests always have greater IDs than older
+    // requests.
+    if (identifier <= find_request_id_counter_)
+      identifier = ++find_request_id_counter_;
+    else
+      find_request_id_counter_ = identifier;
+
     blink::WebFindOptions options;
     options.forward = forward;
     options.match_case = matchCase;
diff --git a/libcef/browser/browser_host_impl.h b/libcef/browser/browser_host_impl.h
index 6f4328eb0..0000eb545 100644
--- a/libcef/browser/browser_host_impl.h
+++ b/libcef/browser/browser_host_impl.h
@@ -637,6 +637,9 @@ class CefBrowserHostImpl : public CefBrowserHost,
   // Observers that want to be notified of changes to this object.
   base::ObserverList<Observer> observers_;
 
+  // Used to provide unique incremental IDs for each find request.
+  int find_request_id_counter_ = 0;
+
   IMPLEMENT_REFCOUNTING(CefBrowserHostImpl);
   DISALLOW_COPY_AND_ASSIGN(CefBrowserHostImpl);
 };