WINGs: Added 'const' attribute to 'WMCreatePropListFromDescription'

To be able to do this in a clean way, it was necessary to add the
attribute also in PLData's ptr field, which is actually right
because none of the function changes its content.

The function that fills it from a file/pipe however needed small
changes to respect the const-ness of the field.

WINGs/WINGs/WUtil.h

@@ -802,7 +802,7 @@ WMPropList* WMShallowCopyPropList(WMPropList *plist);
 /* Makes a completely separate replica of the original proplist */
 WMPropList* WMDeepCopyPropList(WMPropList *plist);
 
-WMPropList* WMCreatePropListFromDescription(char *desc);
+WMPropList* WMCreatePropListFromDescription(const char *desc);
 
 /* Free the returned string when you no longer need it */
 char* WMGetPropListDescription(WMPropList *plist, Bool indented);

WINGs/proplist.c

@@ -36,7 +36,7 @@ typedef struct W_PropList {
 } W_PropList;
 
 typedef struct PLData {
-	char *ptr;
+	const char *ptr;
 	int pos;
 	const char *filename;
 	int lineNumber;
@@ -1469,7 +1469,7 @@ WMPropList *WMDeepCopyPropList(WMPropList * plist)
 	return ret;
 }
 
-WMPropList *WMCreatePropListFromDescription(char *desc)
+WMPropList *WMCreatePropListFromDescription(const char *desc)
 {
 	WMPropList *plist = NULL;
 	PLData *pldata;
@@ -1506,6 +1506,7 @@ WMPropList *WMReadPropListFromFile(const char *file)
 {
 	WMPropList *plist = NULL;
 	PLData *pldata;
+	char *read_buf;
 	FILE *f;
 	struct stat stbuf;
 	size_t length;
@@ -1525,20 +1526,22 @@ WMPropList *WMReadPropListFromFile(const char *file)
 		return NULL;
 	}
 
-	pldata = (PLData *) wmalloc(sizeof(PLData));
+	read_buf = wmalloc(length + 1);
-	pldata->ptr = (char *)wmalloc(length + 1);
+	if (fread(read_buf, length, 1, f) != 1) {
-	pldata->filename = file;
-	pldata->lineNumber = 1;
-
-	if (fread(pldata->ptr, length, 1, f) != 1) {
 		if (ferror(f)) {
 			werror(_("error reading from file '%s'"), file);
 		}
-		plist = NULL;
+		fclose(f);
-		goto cleanup;
+		wfree(read_buf);
+		return NULL;
 	}
+	read_buf[length] = '\0';
+	fclose(f);
 
-	pldata->ptr[length] = 0;
+	pldata = (PLData *) wmalloc(sizeof(PLData));
+	pldata->ptr = read_buf;
+	pldata->filename = file;
+	pldata->lineNumber = 1;
 
 	plist = getPropList(pldata);
 
@@ -1554,10 +1557,8 @@ WMPropList *WMReadPropListFromFile(const char *file)
 		plist = NULL;
 	}
 
- cleanup:
+	wfree(read_buf);
-	wfree(pldata->ptr);
 	wfree(pldata);
-	fclose(f);
 
 	return plist;
 }
@@ -1568,6 +1569,7 @@ WMPropList *WMReadPropListFromPipe(const char *command)
 	WMPropList *plist;
 	PLData *pldata;
 	char line[1024];
+	char *read_buf;
 
 	file = popen(command, "r");
 
@@ -1582,17 +1584,19 @@ WMPropList *WMReadPropListFromPipe(const char *command)
 	pldata->lineNumber = 1;
 
 	/* read from file till EOF or OOM and fill proplist buffer*/
+	read_buf = NULL;
 	while (fgets(line, sizeof(line), file) != NULL) {
-		if (pldata->ptr == NULL) {
+		if (read_buf == NULL) {
-			pldata->ptr = wmalloc(strlen(line)+1);
+			read_buf = wmalloc(strlen(line)+1);
-			pldata->ptr[0] = '\0';
+			read_buf[0] = '\0';
 		} else {
-			pldata->ptr = wrealloc(pldata->ptr,
+			read_buf = wrealloc(read_buf,
-			    strlen(line) + strlen(pldata->ptr) + 1);
+			    strlen(line) + strlen(read_buf) + 1);
 		}
 
-		pldata->ptr = strncat(pldata->ptr, line, strlen(line));
+		read_buf = strncat(read_buf, line, strlen(line));
 	}
+	pldata->ptr = read_buf;
 
 	pclose(file);
 
@@ -1610,7 +1614,7 @@ WMPropList *WMReadPropListFromPipe(const char *command)
 		plist = NULL;
 	}
 
-	wfree(pldata->ptr);
+	wfree(read_buf);
 	wfree(pldata);
 
 	return plist;