From eb7e12b829fbc31f5edd9d27656579183190cafd Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Fri, 24 May 2019 15:57:43 +0000
Subject: [PATCH] Make sure file from a recent menu exists before using it.

Otherwise it can result in a very confusing error that does not
suggest at all that the file is missing.
---
 src/graphicswin.cpp       | 9 +++++++--
 src/platform/platform.cpp | 7 +++++++
 src/platform/platform.h   | 1 +
 src/solvespace.h          | 1 -
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/graphicswin.cpp b/src/graphicswin.cpp
index 0571027..9274439 100644
--- a/src/graphicswin.cpp
+++ b/src/graphicswin.cpp
@@ -345,8 +345,13 @@ static void PopulateMenuWithPathnames(Platform::MenuRef menu,
         menuItem->SetEnabled(false);
     } else {
         for(Platform::Path pathname : pathnames) {
-            Platform::MenuItemRef menuItem = menu->AddItem(pathname.raw,
-                [=]() { onTrigger(pathname); }, /*mnemonics=*/false);
+            Platform::MenuItemRef menuItem = menu->AddItem(pathname.raw, [=]() {
+                if(FileExists(pathname)) {
+                    onTrigger(pathname);
+                } else {
+                    Error(_("File '%s' does not exist."), pathname.raw.c_str());
+                }
+            }, /*mnemonics=*/false);
         }
     }
 }
diff --git a/src/platform/platform.cpp b/src/platform/platform.cpp
index 6eec06c..ab08828 100644
--- a/src/platform/platform.cpp
+++ b/src/platform/platform.cpp
@@ -405,6 +405,13 @@ FILE *OpenFile(const Platform::Path &filename, const char *mode) {
 #endif
 }
 
+bool FileExists(const Platform::Path &filename) {
+    FILE *f = OpenFile(filename, "rb");
+    if(f == NULL) return false;
+    fclose(f);
+    return true;
+}
+
 void RemoveFile(const Platform::Path &filename) {
     ssassert(filename.raw.length() == strlen(filename.raw.c_str()),
              "Unexpected null byte in middle of a path");
diff --git a/src/platform/platform.h b/src/platform/platform.h
index 06ae19f..011dfcc 100644
--- a/src/platform/platform.h
+++ b/src/platform/platform.h
@@ -55,6 +55,7 @@ struct PathLess {
 };
 
 // File manipulation functions.
+bool FileExists(const Platform::Path &filename);
 FILE *OpenFile(const Platform::Path &filename, const char *mode);
 bool ReadFile(const Platform::Path &filename, std::string *data);
 bool WriteFile(const Platform::Path &filename, const std::string &data);
diff --git a/src/solvespace.h b/src/solvespace.h
index 9ba97d6..4e18a74 100644
--- a/src/solvespace.h
+++ b/src/solvespace.h
@@ -138,7 +138,6 @@ enum class Command : uint32_t;
 #include "platform/gui.h"
 
 const size_t MAX_RECENT = 8;
-extern Platform::Path RecentFile[MAX_RECENT];
 
 #define AUTOSAVE_EXT "slvs~"