From f755999c0e5b5b7d92114e94a760211f63b22b96 Mon Sep 17 00:00:00 2001
From: mikee47 <mike@sillyhouse.net>
Date: Sun, 3 Nov 2019 14:10:50 +0000
Subject: [PATCH] Fix `getHostAppDir()`, broken in #1913.

---
 Sming/Arch/Host/Components/hostlib/hostlib.c      | 8 +++++---
 Sming/Arch/Host/Components/hostlib/hostlib.h      | 9 +++++++--
 Sming/Arch/Host/Components/spi_flash/flashmem.cpp | 9 ++++++---
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/Sming/Arch/Host/Components/hostlib/hostlib.c b/Sming/Arch/Host/Components/hostlib/hostlib.c
index 0e53f2ef07..c94357b75a 100644
--- a/Sming/Arch/Host/Components/hostlib/hostlib.c
+++ b/Sming/Arch/Host/Components/hostlib/hostlib.c
@@ -29,10 +29,10 @@ int msleep(unsigned ms)
 	return nanosleep(&req, &rem);
 }
 
-void getHostAppDir(char* path, size_t bufSize)
+size_t getHostAppDir(char* path, size_t bufSize)
 {
 	if(path == NULL ||bufSize == 0) {
-		return;
+		return 0;
 	}
 
 	size_t len;
@@ -46,7 +46,9 @@ void getHostAppDir(char* path, size_t bufSize)
 #endif
 	path[len] = '\0';
 	char* p = strrchr(path, sep);
-	if(p) {
+	if(p != NULL) {
 		p[1] = '\0';
+		len = 1 + p - path;
 	}
+	return len;
 }
diff --git a/Sming/Arch/Host/Components/hostlib/hostlib.h b/Sming/Arch/Host/Components/hostlib/hostlib.h
index 94172cecb3..c2e52a10f5 100644
--- a/Sming/Arch/Host/Components/hostlib/hostlib.h
+++ b/Sming/Arch/Host/Components/hostlib/hostlib.h
@@ -55,8 +55,13 @@ extern "C" {
 
 int msleep(unsigned ms);
 
-// Include trailing path separator
-void getHostAppDir(char* path, size_t bufSize);
+/**
+ * @brief Get directory where application is executing from
+ * @param path Receives directory path, including trailing path separator
+ * @param bufSize
+ * @retval size_t Number of characters written, excluding NUL
+ */
+size_t getHostAppDir(char* path, size_t bufSize);
 
 #ifdef __cplusplus
 }
diff --git a/Sming/Arch/Host/Components/spi_flash/flashmem.cpp b/Sming/Arch/Host/Components/spi_flash/flashmem.cpp
index 4eb3374259..2dfba0694d 100644
--- a/Sming/Arch/Host/Components/spi_flash/flashmem.cpp
+++ b/Sming/Arch/Host/Components/spi_flash/flashmem.cpp
@@ -24,7 +24,7 @@
 static int flashFile = -1;
 static size_t flashFileSize = 0x400000U;
 static char flashFileName[256];
-static const char* defaultFlashFileName = "flash.bin";
+static const char defaultFlashFileName[] = "flash.bin";
 
 #define SPI_FLASH_SEC_SIZE 4096
 
@@ -42,8 +42,11 @@ bool host_flashmem_init(FlashmemConfig& config)
 		strncpy(flashFileName, config.filename, sizeof(flashFileName));
 		flashFileName[sizeof(flashFileName) - 1] = '\0';
 	} else {
-		getHostAppDir(flashFileName, sizeof(flashFileName));
-		strcpy(flashFileName, defaultFlashFileName);
+		size_t len = getHostAppDir(flashFileName, sizeof(flashFileName));
+		if(len + sizeof(defaultFlashFileName) > sizeof(flashFileName)) {
+			return false;
+		}
+		memcpy(&flashFileName[len], defaultFlashFileName, sizeof(defaultFlashFileName));
 		config.filename = flashFileName;
 	}