(svn r14540) -Codechange: introduce [v]seprintf which are like [v]snprintf but do return the number of characters written instead of the number of characters that would be written; as size_t is unsigned substraction can cause integer underflows quite quickly.

1 files changed, 18 insertions, 15 deletions

diff --git a/src/settings.cpp b/src/settings.cpp
index 541a2c480..b3fdc36aa 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -211,10 +211,11 @@ static bool load_intlist(const char *str, void *array, int nelems, VarType type)
 /** Convert an integer-array (intlist) to a string representation. Each value
  * is seperated by a comma or a space character
  * @param buf output buffer where the string-representation will be stored
+ * @param last last item to write to in the output buffer
  * @param array pointer to the integer-arrays that is read from
  * @param nelems the number of elements the array holds.
  * @param type the type of elements the array holds (eg INT8, UINT16, etc.) */
-static void make_intlist(char *buf, const void *array, int nelems, VarType type)
+static void make_intlist(char *buf, const char *last, const void *array, int nelems, VarType type)
 {
 	int i, v = 0;
 	const byte *p = (const byte*)array;
@@ -230,15 +231,16 @@ static void make_intlist(char *buf, const void *array, int nelems, VarType type)
 		case SLE_VAR_U32: v = *(uint32*)p; p += 4; break;
 		default: NOT_REACHED();
 		}
-		buf += sprintf(buf, (i == 0) ? "%d" : ",%d", v);
+		buf += seprintf(buf, last, (i == 0) ? "%d" : ",%d", v);
 	}
 }
 
 /** Convert a ONEofMANY structure to a string representation.
  * @param buf output buffer where the string-representation will be stored
+ * @param last last item to write to in the output buffer
  * @param many the full-domain string of possible values
  * @param id the value of the variable and whose string-representation must be found */
-static void make_oneofmany(char *buf, const char *many, int id)
+static void make_oneofmany(char *buf, const char *last, const char *many, int id)
 {
 	int orig_id = id;
 
@@ -246,7 +248,7 @@ static void make_oneofmany(char *buf, const char *many, int id)
 	while (--id >= 0) {
 		for (; *many != '|'; many++) {
 			if (*many == '\0') { // not found
-				sprintf(buf, "%d", orig_id);
+				seprintf(buf, last, "%d", orig_id);
 				return;
 			}
 		}
@@ -254,16 +256,17 @@ static void make_oneofmany(char *buf, const char *many, int id)
 	}
 
 	/* copy string until next item (|) or the end of the list if this is the last one */
-	while (*many != '\0' && *many != '|') *buf++ = *many++;
+	while (*many != '\0' && *many != '|' && buf < last) *buf++ = *many++;
 	*buf = '\0';
 }
 
 /** Convert a MANYofMANY structure to a string representation.
  * @param buf output buffer where the string-representation will be stored
+ * @param last last item to write to in the output buffer
  * @param many the full-domain string of possible values
  * @param x the value of the variable and whose string-representation must
  *        be found in the bitmasked many string */
-static void make_manyofmany(char *buf, const char *many, uint32 x)
+static void make_manyofmany(char *buf, const char *last, const char *many, uint32 x)
 {
 	const char *start;
 	int i = 0;
@@ -274,10 +277,10 @@ static void make_manyofmany(char *buf, const char *many, uint32 x)
 		while (*many != 0 && *many != '|') many++; // advance to the next element
 
 		if (HasBit(x, 0)) { // item found, copy it
-			if (!init) *buf++ = '|';
+			if (!init) buf += seprintf(buf, last, "|");
 			init = false;
 			if (start == many) {
-				buf += sprintf(buf, "%d", i);
+				buf += seprintf(buf, last, "%d", i);
 			} else {
 				memcpy(buf, start, many - start);
 				buf += many - start;
@@ -556,9 +559,9 @@ static void ini_save_settings(IniFile *ini, const SettingDesc *sd, const char *g
 
 			switch (sdb->cmd) {
 			case SDT_BOOLX:      strcpy(buf, (i != 0) ? "true" : "false"); break;
-			case SDT_NUMX:       sprintf(buf, IsSignedVarMemType(sld->conv) ? "%d" : "%u", i); break;
-			case SDT_ONEOFMANY:  make_oneofmany(buf, sdb->many, i); break;
-			case SDT_MANYOFMANY: make_manyofmany(buf, sdb->many, i); break;
+			case SDT_NUMX:       seprintf(buf, lastof(buf), IsSignedVarMemType(sld->conv) ? "%d" : "%u", i); break;
+			case SDT_ONEOFMANY:  make_oneofmany(buf, lastof(buf), sdb->many, i); break;
+			case SDT_MANYOFMANY: make_manyofmany(buf, lastof(buf), sdb->many, i); break;
 			default: NOT_REACHED();
 			}
 		} break;
@@ -566,16 +569,16 @@ static void ini_save_settings(IniFile *ini, const SettingDesc *sd, const char *g
 		case SDT_STRING:
 			switch (GetVarMemType(sld->conv)) {
 			case SLE_VAR_STRB: strcpy(buf, (char*)ptr); break;
-			case SLE_VAR_STRBQ:sprintf(buf, "\"%s\"", (char*)ptr); break;
+			case SLE_VAR_STRBQ:seprintf(buf, lastof(buf), "\"%s\"", (char*)ptr); break;
 			case SLE_VAR_STR:  strcpy(buf, *(char**)ptr); break;
-			case SLE_VAR_STRQ: sprintf(buf, "\"%s\"", *(char**)ptr); break;
-			case SLE_VAR_CHAR: sprintf(buf, "\"%c\"", *(char*)ptr); break;
+			case SLE_VAR_STRQ: seprintf(buf, "\"%s\"", lastof(buf), *(char**)ptr); break;
+			case SLE_VAR_CHAR: seprintf(buf, "\"%c\"", lastof(buf), *(char*)ptr); break;
 			default: NOT_REACHED();
 			}
 			break;
 
 		case SDT_INTLIST:
-			make_intlist(buf, ptr, sld->length, GetVarMemType(sld->conv));
+			make_intlist(buf, lastof(buf), ptr, sld->length, GetVarMemType(sld->conv));
 			break;
 		default: NOT_REACHED();
 		}