diff --git a/src/gfxlib2/gfx_draw.c b/src/gfxlib2/gfx_draw.c
index 2dce8a332c..611029bf24 100644
--- a/src/gfxlib2/gfx_draw.c
+++ b/src/gfxlib2/gfx_draw.c
@@ -220,9 +220,9 @@ FBCALL void fb_GfxDraw(void *target, FBSTRING *command)
 				move = draw = TRUE;
 				break;
 
-			case 'F': case 'D': angle += 90;
-			case 'G': case 'L': angle += 90;
-			case 'H': case 'U': angle += 90;
+			case 'F': case 'D': angle += 90; /* fall through */
+			case 'G': case 'L': angle += 90; /* fall through */
+			case 'H': case 'U': angle += 90; /* fall through */
 			case 'E': case 'R':
 				diagonal = ((toupper(*c) >= 'E') && (toupper(*c) <= 'H'));
 				c++;
diff --git a/src/gfxlib2/linux/gfx_joystick.c b/src/gfxlib2/linux/gfx_joystick.c
index 2fd4fe5f6c..2c0cc9afd5 100644
--- a/src/gfxlib2/linux/gfx_joystick.c
+++ b/src/gfxlib2/linux/gfx_joystick.c
@@ -34,7 +34,8 @@ FBCALL int fb_GfxGetJoystick(int id, ssize_t *buttons, float *a1, float *a2, flo
 	const char *device[] = { "/dev/input/js",
 							 "/dev/js",
 							 NULL };
-	char device_name[16];
+	/* overallocate device_name[] to prevent a sprintf() warning in GCC */
+	char device_name[13 + 11 + 1];
 	JOYDATA *joy;
 	JS_EVENT event;
 	int i, j, k, count = 0;
diff --git a/src/gfxlib2/win32/gfx_win32.c b/src/gfxlib2/win32/gfx_win32.c
index 204752f1ca..57e0cb0ecc 100644
--- a/src/gfxlib2/win32/gfx_win32.c
+++ b/src/gfxlib2/win32/gfx_win32.c
@@ -89,8 +89,13 @@ static void fb_hSetMouseClip( void )
 	ClipCursor(&rc);
 }
 
-static void ToggleFullScreen( void )
+static void ToggleFullScreen( EVENT *e )
 {
+	if (has_focus) {
+		e->type = EVENT_MOUSE_EXIT;
+		fb_hPostEvent(e);
+	}
+
 	if (fb_win32.flags & DRIVER_NO_SWITCH)
 		return;
 
@@ -322,24 +327,22 @@ LRESULT CALLBACK fb_hWin32WinProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM
 			break;
 
 		case WM_SIZE:
-		case WM_SYSKEYDOWN:
-			if (!fb_win32.is_active)
-				break;
+			if (fb_win32.is_active) {
+				if ( wParam == SIZE_MAXIMIZED ) {
+					ToggleFullScreen(&e);
+					return FALSE;
+				}
+			}
+			break;
 
-			{
-				int is_alt_enter = ((message == WM_SYSKEYDOWN) && (wParam == VK_RETURN) && (lParam & 0x20000000));
-				int is_maximize = ((message == WM_SIZE) && (wParam == SIZE_MAXIMIZED));
-				if ( is_maximize || is_alt_enter) {
-					if (has_focus) {
-						e.type = EVENT_MOUSE_EXIT;
-						fb_hPostEvent(&e);
-					}
-					ToggleFullScreen();
+		case WM_SYSKEYDOWN:
+			if (fb_win32.is_active) {
+				if ( (wParam == VK_RETURN) && (lParam & 0x20000000) ) {
+					ToggleFullScreen(&e);
 					return FALSE;
 				}
-				if( message!=WM_SYSKEYDOWN )
-					break;
 			}
+			/* fall through */
 
 		case WM_KEYDOWN:
 		case WM_KEYUP:
diff --git a/src/rtlib/dev_file_encod_read_core.c b/src/rtlib/dev_file_encod_read_core.c
index 76f0561e47..b078694df9 100644
--- a/src/rtlib/dev_file_encod_read_core.c
+++ b/src/rtlib/dev_file_encod_read_core.c
@@ -36,18 +36,23 @@ static ssize_t hReadUTF8ToChar( FILE *fp, char *dst, ssize_t max_chars )
 			case 5:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 4:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 3:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 2:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 1:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 0:
 				wc += *p++;
 		}
@@ -161,18 +166,23 @@ static ssize_t hUTF8ToUTF16( FILE *fp, FB_WCHAR *dst, ssize_t max_chars )
 			case 5:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 4:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 3:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 2:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 1:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 0:
 				wc += *p++;
 		}
@@ -225,18 +235,23 @@ static ssize_t hUTF8ToUTF32( FILE *fp, FB_WCHAR *dst, ssize_t max_chars )
 			case 5:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 4:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 3:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 2:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 1:
 				wc += *p++;
 				wc <<= 6;
+				/* fall through */
 			case 0:
 				wc += *p++;
 		}
diff --git a/src/rtlib/dos/io_cls.c b/src/rtlib/dos/io_cls.c
index 8f8f4ed656..d1c0445869 100644
--- a/src/rtlib/dos/io_cls.c
+++ b/src/rtlib/dos/io_cls.c
@@ -8,8 +8,9 @@ void fb_ConsoleClear( int mode )
 {
     int toprow, botrow;
 
-    if( mode==1 )
+    if( mode==1 ) {
         return;
+	}
 
 	if( (mode == 2) || (mode == (int)0xFFFF0000) ) {	/* same as gfxlib's DEFAULT_COLOR */
         fb_ConsoleGetView( &toprow, &botrow );
diff --git a/src/rtlib/file_input_tok.c b/src/rtlib/file_input_tok.c
index cfe33068bf..e1e91e0500 100644
--- a/src/rtlib/file_input_tok.c
+++ b/src/rtlib/file_input_tok.c
@@ -192,6 +192,7 @@ int fb_FileInputNextToken
 					goto exit;
 				}
 			}
+			goto savechar;
 
 		default:
 savechar:
diff --git a/src/rtlib/file_input_tok_wstr.c b/src/rtlib/file_input_tok_wstr.c
index 4cddc5dd65..a6d0877047 100644
--- a/src/rtlib/file_input_tok_wstr.c
+++ b/src/rtlib/file_input_tok_wstr.c
@@ -159,6 +159,7 @@ void fb_FileInputNextTokenWstr( FB_WCHAR *buffer, ssize_t max_chars, int is_stri
 					goto exit;
 				}
 			}
+			goto savechar;
 
 		default:
 savechar:
diff --git a/src/rtlib/unix/io_printer.c b/src/rtlib/unix/io_printer.c
index 5a0475eaea..26ca2ae458 100644
--- a/src/rtlib/unix/io_printer.c
+++ b/src/rtlib/unix/io_printer.c
@@ -125,7 +125,7 @@ int fb_PrinterOpen( DEV_LPT_INFO *devInfo, int iPort, const char *pszDeviceRaw )
 
 	} else {
 		/* use direct port io */
-		filename = alloca( 16 );
+		filename = alloca( 7 + 11 + 1 );
 		sprintf(filename, "/dev/lp%d", (devInfo->iPort-1));
 		fp = fopen(filename, "wb");
 
diff --git a/src/rtlib/utf_convfrom_wchar.c b/src/rtlib/utf_convfrom_wchar.c
index b695dba64e..a84407ef73 100644
--- a/src/rtlib/utf_convfrom_wchar.c
+++ b/src/rtlib/utf_convfrom_wchar.c
@@ -37,12 +37,15 @@ static void hUTF16ToUTF8( const FB_WCHAR *src, ssize_t chars, UTF_8 *dst, ssize_
 		case 4:
 			*--dst = ((c | UTF8_BYTEMARK) & UTF8_BYTEMASK);
 			c >>= 6;
+			/* fall through */
 		case 3:
 			*--dst = ((c | UTF8_BYTEMARK) & UTF8_BYTEMASK);
 			c >>= 6;
+			/* fall through */
 		case 2:
 			*--dst = ((c | UTF8_BYTEMARK) & UTF8_BYTEMASK);
 			c >>= 6;
+			/* fall through */
 		case 1:
 			*--dst = (c | __fb_utf8_bmarkTb[bytes]);
 		}
@@ -78,12 +81,15 @@ static void hUTF32ToUTF8( const FB_WCHAR *src, ssize_t chars, UTF_8 *dst, ssize_
 		case 4:
 			*--dst = ((c | UTF8_BYTEMARK) & UTF8_BYTEMASK);
 			c >>= 6;
+			/* fall through */
 		case 3:
 			*--dst = ((c | UTF8_BYTEMARK) & UTF8_BYTEMASK);
 			c >>= 6;
+			/* fall through */
 		case 2:
 			*--dst = ((c | UTF8_BYTEMARK) & UTF8_BYTEMASK);
 			c >>= 6;
+			/* fall through */
 		case 1:
 			*--dst = (c | __fb_utf8_bmarkTb[bytes]);
 		}
diff --git a/src/rtlib/utf_convto_char.c b/src/rtlib/utf_convto_char.c
index c3b615bedc..95c4784e0d 100644
--- a/src/rtlib/utf_convto_char.c
+++ b/src/rtlib/utf_convto_char.c
@@ -26,14 +26,19 @@ char *fb_hUTF8ToChar( const UTF_8 *src, char *dst, ssize_t *chars )
 			{
 				case 5:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 4:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 3:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 2:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 1:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 0:
 					c += *src++;
 			}
@@ -73,14 +78,19 @@ char *fb_hUTF8ToChar( const UTF_8 *src, char *dst, ssize_t *chars )
 			{
 				case 5:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 4:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 3:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 2:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 1:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 0:
 					c += *src++;
 			}
diff --git a/src/rtlib/utf_convto_wchar.c b/src/rtlib/utf_convto_wchar.c
index db6eea02bd..225b031bed 100644
--- a/src/rtlib/utf_convto_wchar.c
+++ b/src/rtlib/utf_convto_wchar.c
@@ -30,14 +30,19 @@ static FB_WCHAR *hUTF8ToUTF16( const UTF_8 *src, FB_WCHAR *dst, ssize_t *chars )
 			{
 				case 5:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 4:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 3:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 2:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 1:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 0:
 					c += *src++;
 			}
@@ -88,14 +93,19 @@ static FB_WCHAR *hUTF8ToUTF16( const UTF_8 *src, FB_WCHAR *dst, ssize_t *chars )
 			{
 				case 5:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 4:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 3:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 2:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 1:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 0:
 					c += *src++;
 			}
@@ -146,14 +156,19 @@ static FB_WCHAR *hUTF8ToUTF32( const UTF_8 *src, FB_WCHAR *dst, ssize_t *chars )
 			{
 				case 5:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 4:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 3:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 2:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 1:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 0:
 					c += *src++;
 			}
@@ -190,14 +205,19 @@ static FB_WCHAR *hUTF8ToUTF32( const UTF_8 *src, FB_WCHAR *dst, ssize_t *chars )
 			{
 				case 5:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 4:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 3:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 2:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 1:
 					c += *src++; c <<= 6;
+					/* fall through */
 				case 0:
 					c += *src++;
 			}