Add an alias for the name for %N to the display sub-structure, so that the name can be varied between displays without having to alter the control value (#165).

src/include/pv-internal.h

@@ -245,6 +245,14 @@ struct pvstate_s {
 	/*****************
 	 * Display state *
 	 *****************/
+	/*
+	 * Note that the "name" pointer is an alias - it should point to
+	 * some other string that's allocated and freed separately, such as
+	 * control.name.  It is used here so that the name can be changed
+	 * for different display structures without having to also change
+	 * the control structure, for example when watching multiple file
+	 * descriptors with --watchfd.
+	 */
 	struct pvdisplay_s {
 
 		struct pvdisplay_segment_s {	/* format string broken into segments */
@@ -273,6 +281,8 @@ struct pvstate_s {
 		off_t initial_offset;			 /* offset when first opened (when watching fds) */
 		size_t next_line_len;				 /* length of currently receiving line so far */
 
+		/*@dependent@*/ /*@null@*/ const char *name; /* copy of pointer to string for %N */
+
 		size_t format_segment_count;	 /* number of format string segments */
 
 		pvtransfercount_t count_type;	 /* type of count for transfer, rate, etc */

src/pv/display.c

@@ -1044,8 +1044,8 @@ bool pv_format(pvprogramstatus_t status, readonly_pvcontrol_t control, readonly_
 		size_t new_size;
 
 		new_size = (size_t) ((4 * control->width) + 80);
-		if (NULL != control->name)
-			new_size += strlen(control->name);	/* flawfinder: ignore */
+		if (NULL != display->name)
+			new_size += strlen(display->name);	/* flawfinder: ignore */
 		/* flawfinder: name is always set by pv_strdup(), which bounds with a \0. */
 
 		new_buffer = malloc(new_size + 16);

src/pv/format/name.c

@@ -35,8 +35,8 @@ pvdisplay_bytecount_t pv_formatter_name(pvformatter_args_t args)
 	(void) pv_snprintf(string_format, sizeof(string_format), "%%%d.500s:", field_width);
 
 	content[0] = '\0';
-	if (args->control->name) {
-		(void) pv_snprintf(content, sizeof(content), string_format, args->control->name);
+	if (args->display->name) {
+		(void) pv_snprintf(content, sizeof(content), string_format, args->display->name);
 	}
 
 	return pv_formatter_segmentcontent(content, args);

src/pv/state.c

@@ -177,6 +177,11 @@ void pv_state_free(pvstate_t state)
 		free(state->display.display_buffer);
 	state->display.display_buffer = NULL;
 
+	if (NULL != state->display.name) {
+		/* The display name pointer is an alias, so don't free it. */
+		state->display.name = NULL;
+	}
+
 	if (NULL != state->extra_display.display_buffer)
 		free(state->extra_display.display_buffer);
 	state->extra_display.display_buffer = NULL;
@@ -299,6 +304,11 @@ void pv_state_set_format(pvstate_t state, bool progress, bool timer, bool eta, b
 	if (NULL != name)
 		state->control.name = pv_strdup(name);
 
+	/*@-onlytrans@ *//* splint correctly warns about possibly leaking memory. */
+	/* Alias this new name pointer, even if it's NULL, to display.name. */
+	state->display.name = state->control.name;
+	/*@+onlytrans@ */
+
 	/* Tell pv_format() that the format has changed. */
 	state->flags.reparse_display = 1;
 }
@@ -442,6 +452,10 @@ void pv_state_name_set(pvstate_t state, /*@null@ */ const char *val)
 	}
 	if (NULL != val)
 		state->control.name = pv_strdup(val);
+	/*@-onlytrans@ *//* splint correctly warns about possibly leaking memory. */
+	/* display.name is an alias - don't free it. */
+	state->display.name = state->control.name;
+	/*@+onlytrans@ */
 }
 
 void pv_state_default_bar_style_set(pvstate_t state, /*@null@ */ const char *val)

src/pv/watchpid.c

@@ -516,6 +516,7 @@ int pv_watchpid_scanfds(pvstate_t state,
 		/*@-mustfreeonly@ *//* splint - this is not a leak, this is a new entry. */
 		info_array[use_idx].state->display.display_buffer = NULL;
 		info_array[use_idx].state->display.display_buffer_size = 0;
+		info_array[use_idx].state->display.name = NULL;
 		info_array[use_idx].state->calc.history = NULL;
 		info_array[use_idx].state->calc.history_len = 0;
 		/*@+mustfreeonly@ */