[groff] 09/11: [grn]: Perform more input validation.

[G. Branden Robinson]

gbranden pushed a commit to branch master
in repository groff.

commit eb4f0675e322d50c69d36625f296f8260fafeb46
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
AuthorDate: Mon Aug 16 11:09:16 2021 +1000

    [grn]: Perform more input validation.
    
    * src/preproc/grn/hdb.cpp: Perform more input validation.  Improve
      diagnostics by taking advantage of libgroff infrastructure and
      tracking the line number of the input file.  Add global `lineno`.
    
      (DBRead): Increment `lineno` after reading newlines from input.  Call
      `error_with_file_and_line()` instead of `error()`.  If input reports a
      negative length for the text (string) to follow in the file, exit with
      a fatal diagnostic.  Check for EOF while reading text string.
    
      (DBGetType): Convert `fprintf()` call for warning diagnostic to
      `warning_with_file_and_line()`.
    
      (DBRead, DBGetType): Add contextual information to diagnostic
      messages.
    
    Fixes <https://savannah.gnu.org/bugs/?61043>.   Thanks to Savannah user
    eqkws for the report.
---
 ChangeLog               | 19 +++++++++++++++++++
 src/preproc/grn/hdb.cpp | 47 ++++++++++++++++++++++++++++++++++++-----------
 2 files changed, 55 insertions(+), 11 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index b8b2a0a..c6c3fa8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,24 @@
 2021-08-16  G. Branden Robinson <g.branden.robinson@gmail.com>
 
+       * src/preproc/grn/hdb.cpp: Perform more input validation.
+       Improve diagnostics by taking advantage of libgroff
+       infrastructure and tracking the line number of the input file.
+       Add global `lineno`.
+       (DBRead): Increment `lineno` after reading newlines from input.
+       Call `error_with_file_and_line()` instead of `error()`.  If
+       input reports a negative length for the text (string) to follow
+       in the file, exit with a fatal diagnostic.  Check for EOF while
+       reading text string.
+       (DBGetType): Convert `fprintf()` call for warning diagnostic to
+       `warning_with_file_and_line()`.
+       (DBRead, DBGetType): Add contextual information to diagnostic
+       messages.
+
+       Fixes <https://savannah.gnu.org/bugs/?61043>.  Thanks to
+       Savannah user eqkws for the report.
+
+2021-08-16  G. Branden Robinson <g.branden.robinson@gmail.com>
+
        * src/preproc/grn/main.cpp (usage): Update usage message.
 
 2021-08-16  G. Branden Robinson <g.branden.robinson@gmail.com>
diff --git a/src/preproc/grn/hdb.cpp b/src/preproc/grn/hdb.cpp
index 77d3ba6..65973e9 100644
--- a/src/preproc/grn/hdb.cpp
+++ b/src/preproc/grn/hdb.cpp
@@ -38,6 +38,7 @@ extern POINT *PTMakePoint(double x, double y, POINT ** 
pplist);
 
 int DBGetType(register char *s);
 
+long lineno = 0;
 
 /*
  * This routine returns a pointer to an initialized database element which
@@ -97,15 +98,18 @@ DBRead(register FILE *file)
   SUNFILE = FALSE;
   elist = DBInit();
   (void) fscanf(file, "%" MAXSTRING_S "s%*[^\n]\n", string);
+  lineno++;
   if (strcmp(string, "gremlinfile")) {
     if (strcmp(string, "sungremlinfile")) {
-      error("'%1' is not a gremlin file", gremlinfile);
+      error_with_file_and_line(gremlinfile, lineno,
+                              "not a gremlin file");
       return (elist);
     }
     SUNFILE = TRUE;
   }
 
   (void) fscanf(file, "%d%lf%lf\n", &size, &x, &y);
+  lineno++;
   /* ignore orientation and file positioning point */
 
   done = FALSE;
@@ -114,9 +118,11 @@ DBRead(register FILE *file)
     /* I changed the scanf format because the element */
     /* can have two words (e.g. CURVE SPLINE)         */
     if (fscanf(file, "\n%" MAXSTRING_S "[^\n]%*[^\n]\n", string) == EOF) {
-      error("'%1', error in file format", gremlinfile);
+      lineno++;
+      error_with_file_and_line(gremlinfile, lineno, "error in format");
       return (elist);
     }
+    lineno++;
 
     type = DBGetType(string);  /* interpret element type */
     if (type < 0) {            /* no more data */
@@ -126,6 +132,7 @@ DBRead(register FILE *file)
       (void) xscanf(file, &x, &y);             /* always one point */
 #else
       (void) fscanf(file, "%lf%lf\n", &x, &y); /* always one point */
+      lineno++;
 #endif /* UW_FASTSCAN */
       plist = PTInit();                /* NULL point list */
 
@@ -146,6 +153,7 @@ DBRead(register FILE *file)
        lastpoint = FALSE;
        do {
          fgets(string, MAXSTRING, file);
+         lineno++;
          if (string[0] == '*') {       /* SUN gremlin file */
            lastpoint = TRUE;
          } else {
@@ -180,6 +188,7 @@ DBRead(register FILE *file)
          savebounds(nx, y);
 
          fgets(string, MAXSTRING, file);
+         lineno++;
          if (string[0] == '*') {       /* SUN gremlin file */
            lastpoint = TRUE;
          } else {
@@ -191,8 +200,15 @@ DBRead(register FILE *file)
 #endif /* UW_FASTSCAN */
       }
       (void) fscanf(file, "%d%d\n", &brush, &size);
+      lineno++;
       (void) fscanf(file, "%d", &len); /* text length */
       (void) getc(file);               /* eat blank */
+      lineno++;                                /* advance line counter early */
+      if (len < 0) {
+       fatal_with_file_and_line(gremlinfile, lineno,
+                               "length claimed for text is nonsense:"
+                               " '%1'", len);
+      }
       txt = (char *) grnmalloc((unsigned) len + 1, "element text");
       for (i = 0; i < len; ++i) {      /* read text */
         int c = getc(file);
@@ -200,6 +216,11 @@ DBRead(register FILE *file)
           break;
        txt[i] = c;
       }
+      if (feof(file)) {
+       fatal_with_file_and_line(gremlinfile, lineno,
+                                "end of file while reading text of"
+                                " length %1", len);
+      }
       txt[len] = '\0';
       (void) DBCreateElt(type, plist, brush, size, txt, &elist);
     }                          /* end else */
@@ -234,8 +255,8 @@ DBGetType(register char *s)
       case 'S': 
        return(BSPLINE);
       case 'E':
-       fprintf(stderr,
-               "Warning: Bezier Curves will be printed as B-Splines\n");
+       warning_with_file_and_line(gremlinfile, lineno,
+                                  "using B-spline for Bezier curve");
        return(BSPLINE);
       default:
        return(CURVE);
@@ -249,8 +270,9 @@ DBGetType(register char *s)
     case 'R':
       return (CENTRIGHT);
     default:
-      fatal("unknown element type");
-      // fatal() does not return
+      fatal_with_file_and_line(gremlinfile, lineno,
+                              "unknown element type '%1'", s);
+      // fatal_with_file_and_line() does not return
     }
   case 'B':
     switch (s[3]) {
@@ -261,8 +283,9 @@ DBGetType(register char *s)
     case 'R':
       return (BOTRIGHT);
     default:
-      fatal("unknown element type");
-      // fatal() does not return
+      fatal_with_file_and_line(gremlinfile, lineno,
+                              "unknown element type '%1'", s);
+      // fatal_with_file_and_line() does not return
     }
   case 'T':
     switch (s[3]) {
@@ -273,11 +296,13 @@ DBGetType(register char *s)
     case 'R':
       return (TOPRIGHT);
     default:
-      fatal("unknown element type");
-      // fatal() does not return
+      fatal_with_file_and_line(gremlinfile, lineno,
+                              "unknown element type '%1'", s);
+      // fatal_with_file_and_line() does not return
     }
   default:
-    fatal("unknown element type");
+    fatal_with_file_and_line(gremlinfile, lineno,
+                            "unknown element type '%1'", s);
   }
 
   return 0;                            /* never reached */