provide less mysterious error messages when seeing end-of-line in

single-quoted strings or end-of-file in triple-quoted strings.
closes patch 586561.

Include/errcode.h

@@ -26,6 +26,8 @@ extern "C" {
 #define E_TOODEEP	20	/* Too many indentation levels */
 #define E_DEDENT	21	/* No matching outer block for dedent */
 #define E_DECODE	22	/* Error in decoding into Unicode */
+#define E_EOFS		23	/* EOF in triple-quoted string */
+#define E_EOLS		24	/* EOL in single-quoted string */
 
 #ifdef __cplusplus
 }

Parser/tokenizer.c

@@ -1276,14 +1276,17 @@ tok_get(register struct tok_state *tok, char **p_start, char **p_end)
 			c = tok_nextc(tok);
 			if (c == '\n') {
 				if (!triple) {
-					tok->done = E_TOKEN;
+					tok->done = E_EOLS;
 					tok_backup(tok, c);
 					return ERRORTOKEN;
 				}
 				tripcount = 0;
 			}
 			else if (c == EOF) {
-				tok->done = E_TOKEN;
+				if (triple)
+					tok->done = E_EOFS;
+				else
+					tok->done = E_EOLS;
 				tok->cur = tok->inp;
 				return ERRORTOKEN;
 			}
@@ -1305,7 +1308,7 @@ tok_get(register struct tok_state *tok, char **p_start, char **p_end)
 				tripcount = 0;
 				c = tok_nextc(tok);
 				if (c == EOF) {
-					tok->done = E_TOKEN;
+					tok->done = E_EOLS;
 					tok->cur = tok->inp;
 					return ERRORTOKEN;
 				}

Python/pythonrun.c

@@ -1247,6 +1247,12 @@ err_input(perrdetail *err)
 	case E_TOKEN:
 		msg = "invalid token";
 		break;
+	case E_EOFS:
+		msg = "EOF while scanning triple-quoted string";
+		break;
+	case E_EOLS:
+		msg = "EOL while scanning single-quoted string";
+		break;
 	case E_INTR:
 		PyErr_SetNone(PyExc_KeyboardInterrupt);
 		Py_XDECREF(v);