From: Ralph Corderoy <ralph@inputplus.co.uk>
Date: Wed, 10 May 2017 11:13:28 +0000 (+0100)
Subject: sbr/fmt_scan.c: Fix `foo%-42{bar}' right-justification bug.
X-Git-Url: https://diplodocus.org/git/nmh/commitdiff_plain/7083c89c5461aa345eec1e47e5fb047d31832c7a

sbr/fmt_scan.c: Fix `foo%-42{bar}' right-justification bug.

The space padding was added at the start of the output buffer, not the
start of the component being formatted.  Caused by 92128dac's move to
dynamic allocation for fmt_scan()'s output.  Only shows if the component
isn't at the start of the buffer.  Expand existing
test/format/test-rightjustify to cover this.
---

diff --git a/sbr/fmt_scan.c b/sbr/fmt_scan.c
index 9377b393..de7d8b78 100644
--- a/sbr/fmt_scan.c
+++ b/sbr/fmt_scan.c
@@ -117,6 +117,7 @@ void
 cptrimmed(charstring_t dest, char *str, int wid, char fill, size_t max) {
     int remaining;     /* remaining output width available */
     int rjust;
+    struct charstring *trimmed;
     size_t end;        /* number of input bytes remaining in str */
 #ifdef MULTIBYTE_SUPPORT
     int char_len;      /* bytes in current character */
@@ -135,6 +136,8 @@ cptrimmed(charstring_t dest, char *str, int wid, char fill, size_t max) {
     }
     if (remaining > (int) max) { remaining = max; }
 
+    trimmed = rjust ? charstring_create(remaining) : dest;
+
     if ((sp = str)) {
 #ifdef MULTIBYTE_SUPPORT
 	if (mbtowc(NULL, NULL, 0)) {} /* reset shift state */
@@ -180,7 +183,7 @@ cptrimmed(charstring_t dest, char *str, int wid, char fill, size_t max) {
 		sp++;
 #endif
 		if (!prevCtrl) {
-		    charstring_push_back (dest, ' ');
+                    charstring_push_back (trimmed, ' ');
 		    remaining--;
 		}
 
@@ -191,39 +194,26 @@ cptrimmed(charstring_t dest, char *str, int wid, char fill, size_t max) {
 
 #ifdef MULTIBYTE_SUPPORT
 	    if (w >= 0 && remaining >= w) {
-		charstring_push_back_chars (dest, altstr ? altstr : sp,
+                charstring_push_back_chars (trimmed, altstr ? altstr : sp,
 					    char_len, w);
 		remaining -= w;
 		altstr = NULL;
 	    }
 	    sp += char_len;
 #else
-	    charstring_push_back (dest, *sp++);
+            charstring_push_back (trimmed, *sp++);
 	    remaining--;
 #endif
 	}
     }
 
-    if (rjust) {
-	if (remaining > 0) {
-	    /* copy string to the right */
-	    charstring_t copy = charstring_copy (dest);
-
-	    /* add padding at the beginning */
-	    charstring_clear (dest);
-	    for (; remaining > 0; --remaining) {
-		charstring_push_back (dest, fill);
-	    }
-
-	    charstring_append (dest, copy);
+    while (remaining-- > 0) {
+        charstring_push_back(dest, fill);
+    }
 
-	    charstring_free (copy);
-	}
-    } else {
-	/* pad remaining space */
-	while (remaining-- > 0) {
-	    charstring_push_back (dest, fill);
-	}
+    if (rjust) {
+        charstring_append(dest, trimmed);
+        charstring_free(trimmed);
     }
 }
 
diff --git a/test/format/test-rightjustify b/test/format/test-rightjustify
index 6ad7e4eb..4dec55ab 100755
--- a/test/format/test-rightjustify
+++ b/test/format/test-rightjustify
@@ -12,16 +12,18 @@ fi
 
 setup_test
 
-actual=`run_prog ${MH_LIBEXEC_DIR}/ap -format "%-30(friendly{text})<<End of test" "No Such User <nosuch@user.com>"`
-expected="                  No Such User<<End of test"
-##########123456789012345678901234567890
+for prefix in '' '>' '2>'; do
+    actual=`run_prog ${MH_LIBEXEC_DIR}/ap -format "$prefix%-20(friendly{text})<<End of test" 'No Such User <nosuch@user.com>'`
+    expected="$prefix        No Such User<<End of test"
+    #                1       10        20
 
-if test x"$actual" != x"$expected"; then
-    echo "$0: right justification test expected:" 1>&2
-    echo "    $expected" 1>&2
-    echo "but instead got:" 1>&2
-    echo "    $actual" 1>&2
-    failed=`expr ${failed:-0} + 1`
-fi
+    if test x"$actual" != x"$expected"; then
+        echo "$0: right justification test expected:" 1>&2
+        echo "    $expected" 1>&2
+        echo "but instead got:" 1>&2
+        echo "    $actual" 1>&2
+        failed=`expr ${failed:-0} + 1`
+    fi
+done
 
 exit $failed