From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 22 Feb 2024 19:43:58 +0000 (+0000)
Subject: utils/gprintf.c: Return the correct number of output characters.
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/commitdiff_plain/912f6431247d27e2144c5c078bd47396d95f5175

utils/gprintf.c: Return the correct number of output characters.

Also fix the test program to check that the output count is correct.
---

diff --git a/struct/t/dstr-putf-test.c b/struct/t/dstr-putf-test.c
index 416b164..044da71 100644
--- a/struct/t/dstr-putf-test.c
+++ b/struct/t/dstr-putf-test.c
@@ -18,13 +18,16 @@ static char strbuf[1024];
 
 #define TESTGROUP(name) TVEC_TESTGROUP_TAG(grp, &tvstate, name)
 
-static void PRINTF_LIKE(1, 2) format(const char *fmt, ...)
+static int PRINTF_LIKE(1, 2) format(const char *fmt, ...)
 {
   va_list ap;
+  int n;
+
   va_start(ap, fmt);
   dstr_reset(&d);
-  dstr_vputf(&d, fmt, &ap);
+  n = dstr_vputf(&d, fmt, &ap);
   va_end(ap);
+  return (n);
 }
 
 static void PRINTF_LIKE(1, 2) prepare(const char *fmt, ...)
@@ -42,14 +45,18 @@ static void PRINTF_LIKE(1, 2) prepare(const char *fmt, ...)
 }
 
 #define TEST_KNOWN(fmtargs, want) do {					\
-  format fmtargs;							\
+  int n; n = format fmtargs;						\
+  tvec_claimeq_int(&tvstate, n, strlen(want),				\
+		   __FILE__, __LINE__, "format " #fmtargs);		\
   tvec_claimeq_string(&tvstate, d.buf, d.len, want, strlen(want),	\
 		      __FILE__, __LINE__, "format " #fmtargs);		\
 } while (0)
 
 #define TEST_REF(fmtargs) do {						\
-  format fmtargs;							\
+  int n = format fmtargs;						\
   prepare fmtargs;							\
+  tvec_claimeq_int(&tvstate, n, strlen(strbuf),				\
+		   __FILE__, __LINE__, "format " #fmtargs);		\
   tvec_claimeq_string(&tvstate, d.buf, d.len, strbuf, strlen(strbuf),	\
 		      __FILE__, __LINE__, "format " #fmtargs);		\
 } while (0)
diff --git a/utils/gprintf.c b/utils/gprintf.c
index b575e1f..8825bd1 100644
--- a/utils/gprintf.c
+++ b/utils/gprintf.c
@@ -416,9 +416,13 @@ int vgprintf(const struct gprintf_ops *ops, void *out,
 
     if (fs->fmt == fmt_unset) {
       switch (fs->ch) {
-	case 0: break;
-	case '%': ops->putch(out, '%'); break;
-	default: abort();
+	case 0:
+	  break;
+	case '%':
+	  if (ops->putch(out, '%')) return (-1);
+	  tot++; break;
+	default:
+	  abort();
       }
       continue;
     }
@@ -497,7 +501,7 @@ int vgprintf(const struct gprintf_ops *ops, void *out,
 #else
 #  define MSG "<no float support>"
 	if (ops->putm(out, MSG, sizeof(MSG) - 1)) return (-1);
-	continue;
+	tot += sizeof(MSG) - 1; continue;
 #  undef MSG
 #endif
       case 's':