Fix crash when #pragma deprecated message is empty

Fixes #283.

source/compiler/sc2.c

@@ -1119,7 +1119,7 @@ static int command(void)
           if (pc_deprecate!=NULL) {
             char *ptr=pc_deprecate+strlen(pc_deprecate)-1;
             /* remove trailing whitespace */
-            while (*ptr<= ' ')
+            while (ptr>=pc_deprecate && *ptr<= ' ')
               *ptr--='\0';
           } else {
             error(103); /* insufficient memory */

source/compiler/tests/CMakeLists.txt

@@ -40,6 +40,11 @@ set_tests_properties(unused_symbol_line_gh_252 PROPERTIES PASS_REGULAR_EXPRESSIO
 .*\\.pwn\\(1\\) : warning 203: symbol is never used: \\\"x\\\"
 ")
 
+add_compiler_test(gh_283 ${CMAKE_CURRENT_SOURCE_DIR}/gh_283.pwn)
+set_tests_properties(gh_283 PROPERTIES PASS_REGULAR_EXPRESSION "\
+.*\\.pwn\\(5\\) : warning 234: function is deprecated \\(symbol \"print\"\\)\
+")
+
 # Crashers
 #
 # These tests simply check that the compiler doesn't crash.

source/compiler/tests/gh_283.pwn

@@ -0,0 +1,6 @@
+#pragma deprecated
+native print(const string[]);
+
+main() {
+	print("Hello World");
+}