libsmartcols: support LIBSMARTCOLS_DEBUG_PADDING=on

This env.variable forces libsmartcols to use visible padding chars.
The standard debug has to be enabled (to minimize overhead for
non-debug execution).

For example:

 $ LIBSMARTCOLS_DEBUG=all LIBSMARTCOLS_DEBUG_PADDING=on findmnt 2> ~/log

Signed-off-by: Karel Zak <kzak@redhat.com>

7 files changed, 28 insertions, 1 deletions

diff --git a/disk-utils/cfdisk.8 b/disk-utils/cfdisk.8
index 68cec9492..6204bdc4f 100644
--- a/disk-utils/cfdisk.8
+++ b/disk-utils/cfdisk.8
@@ -184,6 +184,8 @@ enables libfdisk debug output.
 enables libblkid debug output.
 .IP LIBSMARTCOLS_DEBUG=all
 enables libsmartcols debug output.
+.IP LIBSMARTCOLS_DEBUG_PADDING=on
+use visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
 
 .SH "SEE ALSO"
 .BR fdisk (8),
diff --git a/disk-utils/fdisk.8 b/disk-utils/fdisk.8
index 5d644d8d6..70e88e36a 100644
--- a/disk-utils/fdisk.8
+++ b/disk-utils/fdisk.8
@@ -354,6 +354,8 @@ enables libfdisk debug output.
 enables libblkid debug output.
 .IP LIBSMARTCOLS_DEBUG=all
 enables libsmartcols debug output.
+.IP LIBSMARTCOLS_DEBUG_PADDING=on
+use visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
 
 .SH "SEE ALSO"
 .BR cfdisk (8),
diff --git a/libsmartcols/src/smartcolsP.h b/libsmartcols/src/smartcolsP.h
index c1bb1e07f..01b132752 100644
--- a/libsmartcols/src/smartcolsP.h
+++ b/libsmartcols/src/smartcolsP.h
@@ -157,6 +157,7 @@ struct libscols_table {
 	unsigned int	ascii		:1,	/* don't use unicode */
 			colors_wanted	:1,	/* enable colors */
 			is_term		:1,	/* isatty() */
+			padding_debug	:1,	/* output visible padding chars */
 			maxout		:1,	/* maximize output */
 			header_printed  :1,	/* header already printed */
 			no_headings	:1,	/* don't print header */
diff --git a/libsmartcols/src/table.c b/libsmartcols/src/table.c
index dc3a3016c..10320f0be 100644
--- a/libsmartcols/src/table.c
+++ b/libsmartcols/src/table.c
@@ -38,6 +38,20 @@
 		list_entry_is_last(&(_cl)->cl_columns, &(_tb)->tb_columns)
 
 
+static void check_padding_debug(struct libscols_table *tb)
+{
+	const char *str;
+
+	assert(libsmartcols_debug_mask);	/* debug has to be enabled! */
+
+	str = getenv("LIBSMARTCOLS_DEBUG_PADDING");
+	if (!str || (strcmp(str, "on") != 0 && strcmp(str, "1") != 0))
+		return;
+
+	DBG(INIT, ul_debugobj(tb, "padding debug: ENABLE"));
+	tb->padding_debug = 1;
+}
+
 /**
  * scols_new_table:
  *
@@ -58,6 +72,8 @@ struct libscols_table *scols_new_table(void)
 	INIT_LIST_HEAD(&tb->tb_columns);
 
 	DBG(TAB, ul_debugobj(tb, "alloc"));
+	ON_DBG(INIT, check_padding_debug(tb));
+
 	return tb;
 }
 
diff --git a/libsmartcols/src/table_print.c b/libsmartcols/src/table_print.c
index 910a9137a..bdac0b296 100644
--- a/libsmartcols/src/table_print.c
+++ b/libsmartcols/src/table_print.c
@@ -37,11 +37,13 @@
  * fallback to be more robust and backwardly compatible.
  */
 #define titlepadding_symbol(tb)	((tb)->symbols->title_padding ? (tb)->symbols->title_padding : " ")
-#define cellpadding_symbol(tb)  ((tb)->symbols->cell_padding ? (tb)->symbols->cell_padding: " ")
 #define branch_symbol(tb)	((tb)->symbols->branch ? (tb)->symbols->branch : "|-")
 #define vertical_symbol(tb)	((tb)->symbols->vert ? (tb)->symbols->vert : "|")
 #define right_symbol(tb)	((tb)->symbols->right ? (tb)->symbols->right : "-")
 
+#define cellpadding_symbol(tb)  ((tb)->padding_debug ? "." : \
+				 ((tb)->symbols->cell_padding ? (tb)->symbols->cell_padding: " "))
+
 
 /* This is private struct to work with output data */
 struct libscols_buffer {
diff --git a/misc-utils/findmnt.8 b/misc-utils/findmnt.8
index 3f09b1900..fd26f5e5c 100644
--- a/misc-utils/findmnt.8
+++ b/misc-utils/findmnt.8
@@ -267,6 +267,8 @@ overrides the default location of the mtab file
 enables libmount debug output
 .IP LIBSMARTCOLS_DEBUG=all
 enables libsmartcols debug output
+.IP LIBSMARTCOLS_DEBUG_PADDING=on
+use visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
 .SH AUTHORS
 .nf
 Karel Zak <kzak@redhat.com>
diff --git a/misc-utils/lsblk.8 b/misc-utils/lsblk.8
index 3e74e37ce..d82d232b3 100644
--- a/misc-utils/lsblk.8
+++ b/misc-utils/lsblk.8
@@ -161,6 +161,8 @@ enables libblkid debug output.
 enables libmount debug output.
 .IP LIBSMARTCOLS_DEBUG=all
 enables libsmartcols debug output.
+.IP LIBSMARTCOLS_DEBUG_PADDING=on
+use visible padding characters. Requires enabled LIBSMARTCOLS_DEBUG.
 .SH SEE ALSO
 .BR findmnt (8),
 .BR blkid (8),